Anatomy chapter 2 the chemistry of life

This content is recorded exclusively for Dr. Young's anatomy class. It is not to be uploaded or distributed to any social media sites or streaming sites and not to be used without the permission of Dr. Young. Welcome to chapter two, chemistry of life. So we have to look at a little bit of chemistry. This isn't a chemistry class, but in the body we start small and we walk our way up big. So we're going to start basically at the chemical reaction. level. So we have to look at atoms, we have to look at molecules, we have to look at how they bond together, how they interact with each other, and then we can build from there. So the first thing to look at, atoms and elements. Now when we're looking at matter, matter is anything that has mass like table, pencil, water, and occupies space. So three different main states, solid, liquid, and a gas. Chemistry is going to be the study of matter. So the study of how these interact with each other, the reactions that they're going to have. We're going to focus on reactions mainly in the body. An atom is the smallest unit of matter. It is going to have mass and occupy space. So that makes it the smallest unit of matter. Now based on an atom's protons, neutrons, electrons, we can actually look at our periodic table and determine those things by looking at the periodic table. So all these are labeled just a little bit different and have a little bit different format, but some of them are pretty standard. This isn't going to be something I'm going to test you on. This is more for a chemistry class, but the actual atomic number is going to be the number on top. The symbol is going to be the letter. So for example, this first one has an H, that's hydrogen. Second one, HE, all the way to your right is helium. Some of these are common, kind of straightforward, easy, like number six, C is carbon. However, if we keep going a little bit and we get to number 11, NA is actually sodium, EMG, magnesium. So a lot of our electrolytes that we have in the body you can find on the periodic table. We're really going to look at four major elements off of this chart and here they are. So the most common that we find actually in the body is going to be hydrogen, oxygen, carbon, and nitrogen. We also have seven different minerals and then 13 different trace elements. So we'll look at those two. Alright, chemical bonds. How do atoms actually bond to each other that's going to go into making our molecule or our compounds? So a chemical bond is literally an attraction or sharing between two different atoms. Whenever we have two atoms that are attracted to each other or are going to share and basically kind of hold hands with their electrons, and we'll go through that here in a second. This is going to form a molecule. If it's a molecule, it has to be the same atoms. So two hydrogens, two heliums. If it's a compound, it's going to be from different atoms. So here we have a carbon and four hydrogens going around. The first type of bond we're going to look at is ionic. So... Whenever we're talking about ions, we're really going to be looking at the movement of the electrons that are floating around the actual atom. We can have an atom that becomes a cation or an atom that becomes an anion. A cation is said to be positively charged because it gives up an electron. Electrons have negative charges. If you give up something negative, you become more positive. That's what our cations do. They lose an electron and they become a cation. The anion is going to become more negative. So this is the one that gains the electron or the negative charge. A good example of our ionic bonds is going to be our salts, our sodium chloride especially. Sodium chloride is just run-of-the-mill table salt. Super important in the body. We need it for our electrolyte balance. We need sodium and we need fluoride If we look at our ionic bonds, all atoms want to be as stable as possible. This is where that electron shell starts to come into play. You can see we have rings going around these atoms. There's very specific rules on what makes these atoms stable. On the first ring, it can only hold two electrons. So if I look at my sodium, which has the purple center, If I look at my first string, it has two electrons. Second ring can hold eight electrons. So if you count here, one, two, three, four, five, six, seven, eight, there's eight electrons in that second ring. Now if the first ring's full and the second ring's full, so far that's a stable atom. However, sodium has 11 electrons. So that extra electron goes in the next ring out that can also hold eight electrons. But it's all by itself. It's not stable. That ring's not complete. So what this electron wants to do, it wants to hang out or go to a different atom. So it makes a sodium stable. If we look at chlorine, chlorine, the first ring has two electrons. The second ring has eight. The third ring has one, two, three, four, five, six, seven. It's almost full. All we need is eight to make it full. So sodium and chloride are made for each other. Sodium has an extra electron. Chloride wants to pick it up. So what happens? These two atoms hang out beside each other. And sodium, you can see on the picture to the right, that electron is going to move. to that chlorine and we end up making sodium chloride because these two atoms are going to hang out right beside each other and form an ionic bond. So we're really looking at the bonds here. So how many pairs are they sharing together? The pool is shared equally between all of those electrons. So it's nonpolar. It's not being pulled to one pole or another. Everything's equal. Polar covalent bonds is when you have one atom that's a lot bigger that's actually going to pull on the electrons with a lot more force. Good example, water. And that's what we're going to mainly focus on, our covalent polar group. covalent bonds are going to be water. So here's a good picture. So you can see we have two small hydrogens surrounding this big oxygen. Well this big oxygen is going to pull on the electrons of the hydrogens with a lot more force because it's a lot bigger. So if we look at the picture to the right, what we end up having, oxygen pulls on the electrons stronger, so it's actually bringing in negative charges. So we have a slight negative charge towards the end of the oxygen, and the hydrogens, they're getting those electrons slightly pulled away from them, so you end up having two positive charges on the end of each hydrogen. This is what makes it polar, so it actually has a charge to it because you have one big atom, two small atoms, and the big atom pulls a lot stronger on those electrons than the smaller ones. So hydrogen bonds are what we're really looking at when we look at polar covalent bonds. So polar bond, remember, positive on the hydrogen, negative on the oxygen. Well, if you have two opposite charges, they attract each other. So those negatives on the oxygen are attracted to the positive on the hydrogens, so they actually pull towards each other. This is what causes surface tension on water. If you jump off of a high cliff, or you go water skiing, or you just jump into the pool, if you do a belly flop or hit that water too hard, it hurts. That's because that water, those water molecules are attracted to each other, and they form a surface tension because those negative charges are attracted to the positive charges. Now, once you break those hydrogen bonds, you fall right through. This isn't a real strong bond. straight polar covalent bonds are strong, but just these hydrogen bonds not as strong. So hydrogen bond, this is going to be really important when we start looking at blood. If you take drops of blood and drop it out on the table, it likes to form a droplet. It just doesn't spread out everywhere, it likes to form nice little droplets. That's because 90 plus percent of our blood is, if you take whole blood out, is actually going to be water. it's going to be a good portion of water in there overall. We have a lot of plasma. We need water for a lot of chemical reactions. We're going to need it to actually undergo metabolism. So hydrogen bonds, very, very prevalent in the body. We're also going to see when we look at our DNA, our DNA is held together by hydrogen bonds. All right, we looked at our bonds. Now it's time to look at some chemical reactions. So when we're looking at chemical reactions, there's a couple different terms that we kind of have to get straight. So we have reactants and we have products. Reactants are the ingredients we start with and products are going to be our result. So chemical reaction, if you think about cooking, you start with the ingredients, which are reactants, and you end up with your product, which might be your cake. Those are all chemical reactions that happen in the kitchen. We're going to have a ton of chemical reactions that happen in the body. Now like I said, this isn't a chemistry class. I'm not going to have you balance equations or anything like that, but we do have to at least kind of look and see how chemical reactions work. So a couple things to be mindful of. When you're looking at chemical reactions, you're going to see some arrows. If it's a reversible reaction, Like in this equation down below, it has a double arrow. If you see that double arrow, that means it's a reversible reaction. If it only has a single arrow, it can only go one way or the other. Now, whenever we do write chemical equations down, the reactants are always on the left and the product is always on the right. A couple different types of chemical reactions we have. Chemical reaction can be endergonic or exergonic. If it's endergonic, it requires the input of energy. We have to actually put energy into it to get that chemical reaction to occur. If it's exergonic, then it releases energy or releases heat. A lot of times in the body, energy is released as heat. Now, there's another term for each of these. Endergonic is also called endothermic, and exogonic is also called exothermic. It's going to be the same thing. Now, we can have catabolic reactions, exchange reactions, or anabolic reactions. If we have a catabolic reaction, cats break things. Catabolic reactions in the body are the breakdown of things. We have to do this when we digest food. We have to break it down. Those are catabolic reactions. Exchange reactions is when we just exchange one thing for another. And then anabolic reactions are the buildup. So whenever we want to store energy, store fat, we go through anabolic reactions. So here's just an example of a catabolic reaction. It does have another term for it too. I always say if it doesn't have two or three terms for the same thing, it's not really anatomy. Ah, this is chemistry. but it's chemistry of anatomy. So decomposition reaction is the same thing as catabolic. Decompose is to break down, catabolic is to break down. So here's an example, A plus B, or you started with AB, and then you break it down into A plus B. So you actually broke those reactants down into two new products. This is usually exergonic, it's usually giving off energy. When we break things apart, we... break bonds and we're going to see energy is actually contained within bonds. Exchange, you're just exchanging two things. So here you start with AB plus CD, you end with AD plus BC. So essentially all that we did we replace the D and the B with each other. It's just an exchange. Anabolic reactions, the complete opposite of cannibal. So you start with A plus B and then you put those together and you form AB. This is usually intergonic. This usually requires energy to get that chemical reaction to occur. Now in order to get a chemical reaction to occur, we have to have some activation energy that goes into it. We want to use as little energy as possible, so we can actually use an enzyme to lower that activation energy. And here's a chart. You can see down here we have reactants. We have the amount of energy that it's going to take to get that reaction to occur, that chemical reaction. And then we finally end up with our products. That activation energy has to come from somewhere. So the more activation energy we use, the more energy that we're going to have to create in the long run. So the whole idea here is going to be to use enzymes which are basically going to be just a special protein That helps to lower that now There are some things that we can do to actually increase the amount of chemical reactions without using more energy If we increase the concentration of the reactant, we have a whole bunch of reactant Then the odds are we are going to get product a little easier and also if we increase the temperature The greater you raise the temperature, the more those reactants are going to bump into each other, and the more often those chemical reactions are going to happen. Size and the state or phase of matter will also play a difference. Smaller particles move faster with more energy, and they're going to collide with each other more often, giving you more chemical reactions. Also, it makes a huge difference if it's a solid, a liquid, or a gas. If it's a solid, it's not going to be moving around much. But if it's a gas, it's going to be moving all over the place. Liquid is kind of in between the two. So if we have chemicals in gaseous form, then they're, of course, going to be able to create more chemical reactions a whole lot faster. Catalyst. A catalyst is going to decrease that activation. energy that we need to get the chemical reaction occurring. In our bodies a catalyst is an enzyme. So like I said enzymes are special types of protein that's going to lower the activation energy and when you lower that it actually speeds up the reaction so we get more product in the long run. The nice thing about enzymes when they work in a chemical reaction, it doesn't change the product. It doesn't change the reactant. It just lowers the activation energy and the enzyme doesn't get used up. We can actually use these over and over and over again. And here's a picture basically showing how these enzymes are going to lower that activation energy. So we start with your reactants. And you can see the big red line is how much energy it would normally take without the enzyme. And then the orange underneath is how much it takes with the enzyme. It takes a lot less energy to get the same product. Also, because that slope is a lot lower, the chemical reaction occurs a lot faster. So not only do we use less energy, but we can end up making more product faster because we use that enzyme. Alright, the next thing to look at here in this chapter is going to be inorganic compounds. Water, acid, bases, and salts. So acid-base balance plays a huge role in the homeostasis of our body and keeping it where we want to keep it at. So, looking at a little biochemistry here. When we're talking about inorganic versus organic. Inorganic compounds do not contain carbon with hydrogen bonded to it. Organic compounds do contain carbon. with hydrogen bonding. So for example, if we're looking at inorganic, water is always a real good example. So water is H2O. It's an oxygen with two hydrogens. There's no carbon there. We're going to see the same thing with our acids, bases, and salts. You don't have that carbon-hydrogen bond going on. Water is a universal solvent in our body, which means it's really good at pulling things apart. So we looked at this when we looked at our polar covalent bonds. It has a positive in and a negative in. Water has that big oxygen that pulls those electrons. stronger towards it, which makes it negative, and then the two smaller hydrogens that end up being positive because it's having those negatives pulled away from them. So since you have a positive and negative in, it's really good to attaching to things that are positive and attaching to things that are negative and actually pulling them apart so they actually dissolve in that fluid. So in our blood, there's a ton of water. If you look at the breakdown of whole blood, about 50%, or a little bit better usually, is going to be plasma. Plasma is 90%, at least, usually more than 90%, just water. So there's a high water content even in our blood. Digestive tract, there's also going to be a lot of water. It helps to break things down. Whenever we're looking at catabolic reactions, water plays a big role in actually breaking. those different substances down. So even though water is a really good solvent at breaking things apart, it can only break things apart that are hydrophilic. So philic means loving, hydro means water. So things that are hydrophilic like water. Basically what this means you need a positive charge and a negative charge so the water since it's polar can grab onto both ends and pull it apart. So water is really good at dissolving or being a solvent for other polar molecules. So here in the example, we have sodium chloride in example A. So sodium chloride, we saw sodium. This is going to be an ionic bond for our salt, sodium chloride. The sodium has a positive end. Chloride ends up being negative. It's polar. Water is really good at breaking apart salt. Put salt in water, stir it up, it completely dissolves, completely breaks apart. Second example to give, carbon monoxide. You have a carbon and an oxygen. Carbon's positive, oxygen ends up negative. Really good at pulling that apart. So the big kind of rule here, like dissolves like. So one polar molecule will be really good at dissolving another polar model. Specifically water is what we're talking about most of the time. On the opposite hand, if something is hydrophobic, phobic is fear, hydro is water, has a fear or dislike of water. Oils are always our classic examples. Oils and fats and we see this in cooking all the time. If you take an oil and pull it, pour it in water and stir it up, It might break into smaller droplets, but it doesn't completely dissolve like a salt would or like glucose would. So that tells us that oil is going to be nonpolar. It doesn't have a positive and negative end. Most oils and fats are usually negative all the way around them or neutral. If you don't have those positive and negative ends, then that water can't bind to it and pull it apart. All right, looking at our acids and bases now. So we're still kind of going to start with a base of water, but so water is H2O. So you got two hydrogens and one oxygen. What we can do, we can break one hydrogen off and we end up with one oxygen and hydrogen still bound to each other. This is basically what we're looking at when we're looking at our acids and our bases. If we have more hydrogens just free-floating in our system, it actually makes us more acidic. If we have more of the OH, or hydroxide ions, which is our oxygen and hydrogen still bound to each other, then we actually have more base in our system, or we become more alkalinic. It's basically just another term for base, and that's what we use in the body. We say we become more alkalinic. So when we're looking at acid and bases, it's really looking at how many hydrogens do we have versus how many hydroxide or OH negative ions do we have. Our body, when we actually break down nutrients to make energy or ATP, ATP is going to be what we use for energy, a byproduct of that is actually using hydrogen ions to make that ATP. So we do end up with just by making energy extra hydrogen ions floating around in our system. Now we do have ways to neutralize that which is going to be with our buffer systems that can actually grab on extra hydrogens. Sometimes we combine it with hydroxide and make water, but there's going to be a point where we actually are making more hydrogens than we can handle, or then we have bases or are able to make water fast enough to contain all those hydrogens. So those hydrogen ions build up in our system and we have to have a way to get rid of those extra acids in there. So this diagram is basically just showing you that if you start with water that can disassociate or break up into hydrogen ions to make acids or hydroxide ions to make those bases. So other molecules can actually grab some of those loose hydrogens and they can also grab some of the loose hydroxide ions. So when that happens, this is where we get our different acids and bases from. Basically, acid has a potential to release a hydrogen. Base has a potential to release a hydroxide or OH negative. pH scale. So when we're trying to measure our acid versus our base, we measure pH. So pH has a range of 0 to 14. All this is really looking at is the concentration of hydrogen ions. As you get closer to zero, it means you have a lot more hydrogen. As you get closer to 14, you have less hydrogen and more hydroxide or OH-ions. So here's a really good chart kind of showing you that. So pH of 7 is completely neutral. We have the same number of hydrogen as we do hydroxide, and that's what these bar graphs are kind of showing here. So blood, pure water, milk is usually pretty close to 7. Pure water is right at 7. Blood likes to sit, we like to keep blood at about 7.4. We actually keep it just a little alkalinic because we want it to be neutral. We don't want it to be too acidic. We don't want it to be too basic. As we start getting closer to the zero, here we can see coffee, tomatoes, then we go vinegar, lemon juice, to stomach acid, you increase the number of hydrogen ions. But if you look at hydroxide, there's less and less. So that's why our pH scale is really looking at the number of hydrogen ions. The more loose floating hydrogen ions you have, the more acidic you become. If we go the opposite direction, things like baking soda, ammonia, bleach, these have more hydroxide ion. So, and less hydrogen ion. So the more hydroxide you have, the more basic or alkalinic you're going to become. Buffer systems. So remember, buffer systems buffer the pH. They try and keep it neutral. We do have some three really big buffer systems in the body. We have a carbonic acid or hydroxide carbonic acid buffer system, protein buffer system, and then a phosphate buffer system. You look at those a lot more in physiology. when you really get into acid-base homeostasis. But those are going to be the three main ones we're really going to look at. What they're trying to do, they're trying to keep everything neutral. Most of the time, we're looking at pH of the blood. So blood should have a pH of 7.35 to 7.45. Salts and electrolytes. So electrolytes are really important here again to maintaining the homeostasis in the body. Especially with our nervous system and sending signals throughout the body. When you do look at how the nervous system sends signals, here again mainly in physiology is where you're going to look at the most. You're going to need the different electrolytes in certain concentrations so our body can create electrical signals. We actually create electricity by manipulating the different electrolytes in our body. So a good example of electrolyte is sodium chloride, is that salt. So you have one in positive, one in negative, you put it in water, they get pulled apart. So then you have positive sodiums and you're going to have negative chlorides. If you split those apart and you have a whole bunch of positives in one area and a whole bunch of negatives in another, you kind of just set up the potential to make a battery. Battery has a positive in and a negative in. You can create a charge and that charge can move through the back. That's what we're going to do with our cells. We're going to take the sodium. basically pile it up on the outside of the cell and take the chloride and keep it inside the cell or more commonly it's potassium sodium is on the outside potassium is on the inside and then we have a whole bunch of negative proteins that are going to be on the inside of a cell to using the sodium potassium chloride and those negative proteins we can actually end up making a positive area and a negative area And our cells are basically set up like tiny batteries, so they can actually create electrical charge. There again, that's going to be something you look at a lot more in physiology. This is just giving you a little introduction to it. Now we're going to look at our organic compounds. So these are going to be compounds that contain those carbon-hydrogen bonds. So our main ones in the body, carbohydrates, lipids, proteins, and then our nucleic acids or nucleotides. Now these can all come in monomers or polymers. If it's a monomer, it's a single unit. But we can put these together to make polymers or to make bigger units if we're going to store them in the bottle. So the way we do this is by dehydration synthesis. If you dehydrate something, you pull the water out. Well, if we pull the water out, we can combine these different subunits together to make long. chains. On the opposite end, if we want to break them apart and actually use them for energy, we can use hydrolysis. You put the water back in, it breaks the bonds and you end up with those smaller subunits that we can then use to make ATP or make energy out of. So looking at our carbohydrates, things that we usually think of as carbohydrates, breads, potato chips, french fries, These are carbohydrates. This is going to be the main energy source for the body, is going to be our carbohydrates. Now, monosaccharides are usually three to seven carbon chains long. I'm not too terribly concerned that you memorize that. That's more of a chemistry thing. But just know a monosaccharide is basically one unit. If it's a polysaccharide, poly means many, it's going to be a lot of these units actually linked together. But some examples of monosaccharide, glucose. Glucose is a carbohydrate. It's a monosaccharide. Fructose, which is basically the mirror image of glucose, we find that actually in fruits. It's the glucose that we find in fruits. It's what makes fruits sweet. So there's a lot of different variations of monosaccharides. Galactose, ribose, deoxyribose. These are all just different forms of a monosaccharide. So here's just showing you the different forms. Here again, I don't necessarily care that you memorize the different forms. You're not gonna have to name them or anything like that. I just wanted to give you some examples of them. Now if we want to put these together to eventually make a polysaccharide. So here we start with glucose and fructose. These are both monosaccharides. If we want to bond these together, We go through dehydration synthesis, which is this top arrow. We take the water out, you dehydrate it, and you can actually link these together. And now it's a disaccharide. You have two units linked. Di means two. If you added a third, then that's where you're going to get your polysaccharide. Or, if you want to break it down, you can go through hydrolysis, which is this bottom arrow. Put the water back in, break them apart. and then you have your fructose and your glucose again. So we can build stuff up, we can break it down. Usually if we're building it up we're going to be storing it so we can use it later. If we're breaking it down we're usually breaking it down so we can use it for energy. So like I said polysaccharide is just combining multiple of these mono disaccharides together to make nice long chains. With our carbohydrates, especially glucose, the way that we store it mainly in the body is as glycogen. We store a ton of glycogen in the muscle. We store a lot in our liver. Since this is the main form of energy in the body, we need a ton of energy for our muscles. In order to be able to move, we need to be able to break small monosaccharides off of that big long polysaccharide chain. So we store it as glycogen. And this just kind of shows you a little pic picture of glycogen. All this is is glucose Combine together in nice big long chains. We can store it and then use it as we need it. Lipids. So lipids actually can make a lot more energy than glucose or carbohydrates can because they're a lot bigger molecule. However, it takes a lot more energy to break these down. Remember glucose? If you put sugar in water and stir it up, it completely dissolves. That's because glucose is going to be a polar molecule. It has positive ends and negative ends. Lipids don't do that. They don't completely dissolve. So they're going to be a non-polar molecule. We can still break them apart and use them for energy, and we do all the time. It's just a lot harder to do that. That's why the carbohydrate is our main source of energy, even though we can actually get more energy out of lipids just because they're so much larger. So here's a picture of a saturated lipid and you hear a lot about saturated versus unsaturated lipids a lot. A saturated lipid has a row of carbons and every single carbon is completely full with hydrogens attached to it. That's why it's called saturated. This is a solid At room temperature, there's no double bonds. It has the maximum number of hydrogen bonds. Here, this is a monosaturated or unsaturated. Sometimes, a lot of times, just in the food world, it's an unsaturated fat. We kind of like unsaturated fats better because these are liquid at room temperature, and they're a little easier to break apart because they... have a double bond, it makes a little kink in the molecule. That little kink, since it's not completely saturated with hydrogens, actually makes it easier to break into two separate chains. That's why a lot of foods will be labeled unsaturated or unsaturated fats. It's actually easier for our body to handle than the saturated fats are. So a lot of foods anymore have unsaturated fats in them. And here's just another one. So this is polyunsaturated. It has multiple double chains. The more double bonds you can get, the more areas that we can break it apart and the easier it is to break apart. So this is what we generally see in a lot of the foods we eat now. So here's a triglyceride. It's basically just a variation of what we just looked at. So it has a glycerol head and three fatty acid tells attached to it. So triglycerides Whenever we're doing a cholesterol panel, we measure triglycerides. Triglycerides are basically three fats attached to a glycerol. These are relatively large molecules, and they can clog up our arteries, leading to things like heart attacks. So we don't want those triglyceride levels to be really high, because they cause a lot of problems. They have a lot of potential energy in them, but too many of them can be a really bad thing. So there are all different kinds of lipids. So phospholipids, we need lipids. We need fat in our diet. When we look at how our cells are put together, all our cells have a biphospholipid membrane to it. Keeps everything on the inside we want in the inside and everything on the outside that we want to keep on the outside. So we have to have lipids in our diet just to maintain the health of our cells. Now here's a phospholipid. All of our phospholipids have a phosphate head and they have two fatty tails to them. This is going to be a molecule that has a polar head and then nonpolar tails. It makes for a really good watertight barrier. Like I said, we're going to look at this more when we look at cell structure and how... These actually make up that cell membrane, but just another type of lipid is basically what this is. So steroids are also a type of lipid. Cholesterol is a type of lipid. These sometimes aren't necessarily always. They don't have to be always chains or tells of fatty acids. They can make up what's called a four-ring hydrocarbon structure. Basically, it just makes up a ring. So we see that in our steroids. A lot of our cholesterol. will also be formed that way and when we look at the liver we'll look at how cholesterol is processed and basically how we take fats and turn it into cholesterol we need that cholesterol in our system there again to maintain basically just those cells so there's a lot of different forms a lot of very different variations of our lipids also next up are proteins proteins are everywhere in the body almost everything is made up of a protein somehow, some way. Enzymes are made up of proteins. All of our cells are made up of different proteins. Our immunoglobulins that we're going to use in our immune system are made of proteins. We can break proteins down and use them for energy. Proteins are just everywhere. We're going to use them as buffers. Proteins can grab hydrogen ions and actually buffer our pH. So proteins are just absolutely everywhere in the body. We have 20 different amino acids that can be linked together. When these amino acids are linked together, they're linked together by what's called a peptide bond. So we actually form polypeptides when we link multiple amino acids together. And then these polypeptides, these are what are actually our proteins, or what we refer to as a protein. So since we have 20 of them, we can put these together in a lot of different combinations. That's why there's so many different functions for proteins, and we find them throughout the entire body doing so many different things. Because there are so many different combinations that we can combine these into, and then they have different functions depending on how we put them together in those different ways. So here again, we still put them together the same way we did whenever we looked at our glucose or carbohydrates. Lipids can do the same way. We didn't look at them in this sense. But we can actually link those lipids together, store them as fat, or break them down still using dehydration synthesis or hydrolysis. So here we have alanine and glycine, which are two different amino acids. If we go through dehydration synthesis, which is our top arrow, we take the water out, we link the carbon and nitrogen together through a peptide bond. We now have a dipeptide. If we want to break them apart, we look at the bottom arrow, go through hydrolysis, put the water back in, and now we have lysine and alanine, two amino acids again. So we can store it or we can break it down. So dipeptide, we just looked at, it's basically just two connected together. You can also have a tripeptide, which is three, or polypeptide gets into 10 or more amino acids. These are making up our proteins. So a protein consists of one or more polypeptide chain. So it's just chain of those amino acids put together, depending on how they're put together, is going to determine their function. and we're going to see that over and over again in the entire body. How something is put together, the structure of it, is going to determine its function in the actual body. If a muscle wasn't put together a certain way, we wouldn't be able to move, it wouldn't be able to contract, and we wouldn't be able to get around. If a nerve could send electrical signals if it wasn't put together that way, we wouldn't be able to feel temperature changes or feel pain. So how something is made, how it's put together, is going to determine its function. So just like we saw with our carbohydrates, with our lipids, there's a bunch of different types of protein. You can have fibrous proteins, you can have globular proteins. Fibrous proteins tend to make up fibers. Globular proteins are globs. And we're going to look at a couple different examples of each one. Proteins become more and more complex with their structure and we have a way to organize these. And that's what the next slide is actually going to show. So when we're looking at protein structure it kind of builds on itself. So here you can see we're going to start with primary protein structure. Primary structure is just a chain of amino acids forming a polypeptide. That's it. A straight chain is primary structure. Secondary structure Those chains can form what's called a beta-pleated sheet or an alpha helix. This becomes important because an alpha helix is actually what makes up our DNA. A beta-pleated sheet, if you think about taking a piece of paper and folding it multiple times on itself and kind of making an accordion type thing with it, that's a beta-pleated sheet. So those are the two forms. that proteins can take if they're in secondary structure. Now, if you go up to tertiary structure, which is this third one, this is when you get into your globular proteins and your fibrous proteins. Basically, all you're doing, you're taking multiple beta-pleated sheets and alpha helixes, putting them together, and either making a globular protein or a fibrous protein. Quaternary structure. Quaternary structure is where we're going to have multiple globular proteins, multiple fibrous proteins, all intermingling with each other and all working together. When we look at hemoglobin in the blood, it's a globular protein. Hemoglobin carries oxygen. It really is what makes our red blood cells red blood cells. And that hemoglobin is just a type of protein that is made to actually bind oxygen and move it through the body. Like I said, proteins, ton of different functions throughout the entire body. We're going to find them everywhere. Proteins can be kind of fragile sometimes. They go through what's called denaturization. The main things that will cause this denaturization is basically just a breakdown. It causes the proteins to break down. pH changes and temperature changes. are going to be the two main things that really cause this in the body. This is why we have to make sure our temperatures don't get too much above 104 degrees Fahrenheit. Once you get above 104, you get into 105, 106, those proteins start to break down. Well, proteins are making up almost all the cells in our body. Our blood has hemoglobin in it. It's a protein. All of our cells are going to have different proteins. proteins in them. If that temperature gets to 105, 106, and those proteins start to break down, that means the cells start to break down and start to die. And the worst part, the proteins that are affected first are actually proteins that are found in our brain. So if those proteins start to break down in our brain, the brain's controlling everything else. It's just kind of a domino effect from there on out. So... Really have to watch that temperature, but pH changes. If our body becomes too acidic, then it also starts to break down those proteins. So we really want to make sure we stay in that homeostatic range. All right, last but not least is going to be our nucleotides. So nucleotides are going to be a nucleic acid. I, their name because they're found in the. nuclei of the cells or the nucleus of the cells, that's why they're called nucleotides, this is what's going to really make up the majority of our DNA and our RNA will be these nucleotides. So a nucleotide has a nitrogen base, it's formed in a hydrocarbon ring, five carbon pentose sugar, and then a phosphate group. And here this isn't something again that you need to memorize. But you can see a little picture of it. You have the nitrogen base, you have a pentose or a five carbon ring sugar, and then you got a phosphate. That's what's making up that nucleic acid or nucleotide. Now with our nucleotides, we only have five different nucleotides. So we don't have 20 like you did with the proteins. These can be broken down into groups. You have your purines and then your primidines. Purines are adenine and guanine and we usually abbreviate those with an A for adenine and G for guanine. Primidines are cytosine, uracil, and thymine. Now, here again we just abbreviate those with their first letters, so cytosine C, uracil U, and thymine T. The reason why we break these into groups is basically just based on their structure. These have very specific pairing patterns that goes with In our DNA, we only find adenine, guanine, cytosine, and thymine. Adenine will always pair up with thymine, so A's always goes with T's, and guanine will always pair with cytosines, or G's always goes with C's. Uracil is only found in RNA. It actually takes the place of our thymine. You don't find thymine in RNA. So we have the same pairing patterns. Guanine still matches with cytosine in RNA. But now adenine will match up with uracil in RNA because it took the place of thymine. Another area other than just our DNA where we see these is actually when we make energy in the body. Adenosine triphosphate is one of those... adenines we just talked about with three phosphate molecules attached to it. Now you can't have just one phosphate or two phosphates or three. So if it's just one phosphate it's adenosine monophosphate. When you attach the second one it becomes adenosine diphosphate and then when you attach the third one it becomes adenosine triphosphate. We abbreviate these. Adenosine monophosphate is AMP. Adenosine diphosphate is ADP. Adenosine triphosphate is ATP. ATP is what we use as energy in the body. The reason why we say this is what we use for the energy is because we're going to store energy in bonds. So the more phosphate you add to it, the more bonds you create. When you break that bond... it's going to release the energy. And a lot of times when we say energy, we kind of mean heat in the body. So a lot of times it's going to release the energy or the heat, and then we can use that heat to speed up chemical reactions. Because remember, the higher the temperature, the faster a chemical reaction can occur. That's going to be work in the body, actually creating those chemical reactions. This is just showing you that the energy is stored in those bonds. So when we do add those phosphates, we're actually storing energy in the bond. When we break the bond or break those phosphates off, the energy is actually coming out. So that's where that energy is really coming. Here's our DNA. So we talked about DNA in that first nucleotide nucleic acid slide. This is where all of our genes or instructions are written. Basically how to make everything in the body. All of our proteins, all of our cells, all the instructions are stored in these nucleic acids and basically the different pattern that they're going to be arranged in. When we are looking at the DNA, we have that pentose sugar, we have that phosphate group, and then we're going to have our nucleic acids. So we have our adenine, our guanine, our cytosine, and our thymine when we're looking at DNA pairing together. So like I said before, these have very specific pairing patterns, and that's what this is showing, right? So we have this double helix that wraps around each other, and if you look at the pattern going down it, if you start at the top, G pairs with C. T pairs with A, C pairs with G, T pairs with A. Your A's and T's always go together, your C's and G's always go together. Now depending on the pattern that they're actually pairing up all the way down here. So here you have a G, a T, a C, a T, a C, an A. That's kind of making up its own alphabet going all the way down. Those are instructions on that particular piece of DNA coding. on how to make an amino acid. Those amino acids are put together to make proteins. Proteins will be put together to make basically all different parts of our cells. So literally the instructions are written in that DNA with those different letters. And here again this is just going over the pairing patterns with you. So A always goes with T, C always goes with C. This is called complementary bass pairing is what it's called. So the A's complement the T's, the C's complement the G's. Like I said earlier, in RNA, you're only going to have uracil. You don't have thiamine. Still works the same way, except you're replacing uracil with thiamine. So now A pairs with U, C will still pair with G. Now RNA is actually going to be... used in a process called transcription and translation. This is what really codes for most of our proteins. What we're going to do, we're actually going to use this, and we're going to take it to a ribosome, which is going to be an organelle we talk about in the cells, and we're going to look at this process more when we do look at cells a little bit. And this eventually is going to be responsible for making the proteins in our body, going through transcription and translation using this RNA. And here's just a picture of both our DNA and our RNA put side by side. We're still using the nucleic acids for both of these. The pairing is really similar, it's just we have uracil in our RNA and thiamine in our DNA.

So we have to look at a little bit of chemistry. This isn't a chemistry class, but in the body we start small and we walk our way up big. So we're going to start basically at the chemical reaction.

level. So we have to look at atoms, we have to look at molecules, we have to look at how they bond together, how they interact with each other, and then we can build from there. So the first thing to look at, atoms and elements.

Now when we're looking at matter, matter is anything that has mass like table, pencil, water, and occupies space. So three different main states, solid, liquid, and a gas. Chemistry is going to be the study of matter. So the study of how these interact with each other, the reactions that they're going to have.

We're going to focus on reactions mainly in the body. An atom is the smallest unit of matter. It is going to have mass and occupy space.

So that makes it the smallest unit of matter. Now based on an atom's protons, neutrons, electrons, we can actually look at our periodic table and determine those things by looking at the periodic table. So all these are labeled just a little bit different and have a little bit different format, but some of them are pretty standard.

This isn't going to be something I'm going to test you on. This is more for a chemistry class, but the actual atomic number is going to be the number on top. The symbol is going to be the letter.

So for example, this first one has an H, that's hydrogen. Second one, HE, all the way to your right is helium. Some of these are common, kind of straightforward, easy, like number six, C is carbon. However, if we keep going a little bit and we get to number 11, NA is actually sodium, EMG, magnesium. So a lot of our electrolytes that we have in the body you can find on the periodic table.

We're really going to look at four major elements off of this chart and here they are. So the most common that we find actually in the body is going to be hydrogen, oxygen, carbon, and nitrogen. We also have seven different minerals and then 13 different trace elements.

So we'll look at those two. Alright, chemical bonds. How do atoms actually bond to each other that's going to go into making our molecule or our compounds?

So a chemical bond is literally an attraction or sharing between two different atoms. Whenever we have two atoms that are attracted to each other or are going to share and basically kind of hold hands with their electrons, and we'll go through that here in a second. This is going to form a molecule.

If it's a molecule, it has to be the same atoms. So two hydrogens, two heliums. If it's a compound, it's going to be from different atoms.

So here we have a carbon and four hydrogens going around. The first type of bond we're going to look at is ionic. So...

Whenever we're talking about ions, we're really going to be looking at the movement of the electrons that are floating around the actual atom. We can have an atom that becomes a cation or an atom that becomes an anion. A cation is said to be positively charged because it gives up an electron. Electrons have negative charges.

If you give up something negative, you become more positive. That's what our cations do. They lose an electron and they become a cation.

The anion is going to become more negative. So this is the one that gains the electron or the negative charge. A good example of our ionic bonds is going to be our salts, our sodium chloride especially. Sodium chloride is just run-of-the-mill table salt. Super important in the body.

We need it for our electrolyte balance. We need sodium and we need fluoride If we look at our ionic bonds, all atoms want to be as stable as possible. This is where that electron shell starts to come into play. You can see we have rings going around these atoms. There's very specific rules on what makes these atoms stable.

On the first ring, it can only hold two electrons. So if I look at my sodium, which has the purple center, If I look at my first string, it has two electrons. Second ring can hold eight electrons. So if you count here, one, two, three, four, five, six, seven, eight, there's eight electrons in that second ring.

Now if the first ring's full and the second ring's full, so far that's a stable atom. However, sodium has 11 electrons. So that extra electron goes in the next ring out that can also hold eight electrons. But it's all by itself.

It's not stable. That ring's not complete. So what this electron wants to do, it wants to hang out or go to a different atom. So it makes a sodium stable.

If we look at chlorine, chlorine, the first ring has two electrons. The second ring has eight. The third ring has one, two, three, four, five, six, seven.

It's almost full. All we need is eight to make it full. So sodium and chloride are made for each other.

Sodium has an extra electron. Chloride wants to pick it up. So what happens?

These two atoms hang out beside each other. And sodium, you can see on the picture to the right, that electron is going to move. to that chlorine and we end up making sodium chloride because these two atoms are going to hang out right beside each other and form an ionic bond.

So we're really looking at the bonds here. So how many pairs are they sharing together? The pool is shared equally between all of those electrons.

So it's nonpolar. It's not being pulled to one pole or another. Everything's equal.

Polar covalent bonds is when you have one atom that's a lot bigger that's actually going to pull on the electrons with a lot more force. Good example, water. And that's what we're going to mainly focus on, our covalent polar group. covalent bonds are going to be water.

So here's a good picture. So you can see we have two small hydrogens surrounding this big oxygen. Well this big oxygen is going to pull on the electrons of the hydrogens with a lot more force because it's a lot bigger.

So if we look at the picture to the right, what we end up having, oxygen pulls on the electrons stronger, so it's actually bringing in negative charges. So we have a slight negative charge towards the end of the oxygen, and the hydrogens, they're getting those electrons slightly pulled away from them, so you end up having two positive charges on the end of each hydrogen. This is what makes it polar, so it actually has a charge to it because you have one big atom, two small atoms, and the big atom pulls a lot stronger on those electrons than the smaller ones. So hydrogen bonds are what we're really looking at when we look at polar covalent bonds. So polar bond, remember, positive on the hydrogen, negative on the oxygen.

Well, if you have two opposite charges, they attract each other. So those negatives on the oxygen are attracted to the positive on the hydrogens, so they actually pull towards each other. This is what causes surface tension on water.

If you jump off of a high cliff, or you go water skiing, or you just jump into the pool, if you do a belly flop or hit that water too hard, it hurts. That's because that water, those water molecules are attracted to each other, and they form a surface tension because those negative charges are attracted to the positive charges. Now, once you break those hydrogen bonds, you fall right through. This isn't a real strong bond. straight polar covalent bonds are strong, but just these hydrogen bonds not as strong.

So hydrogen bond, this is going to be really important when we start looking at blood. If you take drops of blood and drop it out on the table, it likes to form a droplet. It just doesn't spread out everywhere, it likes to form nice little droplets. That's because 90 plus percent of our blood is, if you take whole blood out, is actually going to be water.

it's going to be a good portion of water in there overall. We have a lot of plasma. We need water for a lot of chemical reactions.

We're going to need it to actually undergo metabolism. So hydrogen bonds, very, very prevalent in the body. We're also going to see when we look at our DNA, our DNA is held together by hydrogen bonds.

All right, we looked at our bonds. Now it's time to look at some chemical reactions. So when we're looking at chemical reactions, there's a couple different terms that we kind of have to get straight.

So we have reactants and we have products. Reactants are the ingredients we start with and products are going to be our result. So chemical reaction, if you think about cooking, you start with the ingredients, which are reactants, and you end up with your product, which might be your cake.

Those are all chemical reactions that happen in the kitchen. We're going to have a ton of chemical reactions that happen in the body. Now like I said, this isn't a chemistry class. I'm not going to have you balance equations or anything like that, but we do have to at least kind of look and see how chemical reactions work. So a couple things to be mindful of.

When you're looking at chemical reactions, you're going to see some arrows. If it's a reversible reaction, Like in this equation down below, it has a double arrow. If you see that double arrow, that means it's a reversible reaction. If it only has a single arrow, it can only go one way or the other.

Now, whenever we do write chemical equations down, the reactants are always on the left and the product is always on the right. A couple different types of chemical reactions we have. Chemical reaction can be endergonic or exergonic.

If it's endergonic, it requires the input of energy. We have to actually put energy into it to get that chemical reaction to occur. If it's exergonic, then it releases energy or releases heat. A lot of times in the body, energy is released as heat.

Now, there's another term for each of these. Endergonic is also called endothermic, and exogonic is also called exothermic. It's going to be the same thing.

Now, we can have catabolic reactions, exchange reactions, or anabolic reactions. If we have a catabolic reaction, cats break things. Catabolic reactions in the body are the breakdown of things.

We have to do this when we digest food. We have to break it down. Those are catabolic reactions. Exchange reactions is when we just exchange one thing for another.

And then anabolic reactions are the buildup. So whenever we want to store energy, store fat, we go through anabolic reactions. So here's just an example of a catabolic reaction. It does have another term for it too.

I always say if it doesn't have two or three terms for the same thing, it's not really anatomy. Ah, this is chemistry. but it's chemistry of anatomy. So decomposition reaction is the same thing as catabolic.

Decompose is to break down, catabolic is to break down. So here's an example, A plus B, or you started with AB, and then you break it down into A plus B. So you actually broke those reactants down into two new products. This is usually exergonic, it's usually giving off energy. When we break things apart, we...

break bonds and we're going to see energy is actually contained within bonds. Exchange, you're just exchanging two things. So here you start with AB plus CD, you end with AD plus BC.

So essentially all that we did we replace the D and the B with each other. It's just an exchange. Anabolic reactions, the complete opposite of cannibal. So you start with A plus B and then you put those together and you form AB. This is usually intergonic.

This usually requires energy to get that chemical reaction to occur. Now in order to get a chemical reaction to occur, we have to have some activation energy that goes into it. We want to use as little energy as possible, so we can actually use an enzyme to lower that activation energy. And here's a chart.

You can see down here we have reactants. We have the amount of energy that it's going to take to get that reaction to occur, that chemical reaction. And then we finally end up with our products. That activation energy has to come from somewhere.

So the more activation energy we use, the more energy that we're going to have to create in the long run. So the whole idea here is going to be to use enzymes which are basically going to be just a special protein That helps to lower that now There are some things that we can do to actually increase the amount of chemical reactions without using more energy If we increase the concentration of the reactant, we have a whole bunch of reactant Then the odds are we are going to get product a little easier and also if we increase the temperature The greater you raise the temperature, the more those reactants are going to bump into each other, and the more often those chemical reactions are going to happen. Size and the state or phase of matter will also play a difference.

Smaller particles move faster with more energy, and they're going to collide with each other more often, giving you more chemical reactions. Also, it makes a huge difference if it's a solid, a liquid, or a gas. If it's a solid, it's not going to be moving around much. But if it's a gas, it's going to be moving all over the place.

Liquid is kind of in between the two. So if we have chemicals in gaseous form, then they're, of course, going to be able to create more chemical reactions a whole lot faster. Catalyst. A catalyst is going to decrease that activation.

energy that we need to get the chemical reaction occurring. In our bodies a catalyst is an enzyme. So like I said enzymes are special types of protein that's going to lower the activation energy and when you lower that it actually speeds up the reaction so we get more product in the long run.

The nice thing about enzymes when they work in a chemical reaction, it doesn't change the product. It doesn't change the reactant. It just lowers the activation energy and the enzyme doesn't get used up. We can actually use these over and over and over again.

And here's a picture basically showing how these enzymes are going to lower that activation energy. So we start with your reactants. And you can see the big red line is how much energy it would normally take without the enzyme.

And then the orange underneath is how much it takes with the enzyme. It takes a lot less energy to get the same product. Also, because that slope is a lot lower, the chemical reaction occurs a lot faster. So not only do we use less energy, but we can end up making more product faster because we use that enzyme.

Alright, the next thing to look at here in this chapter is going to be inorganic compounds. Water, acid, bases, and salts. So acid-base balance plays a huge role in the homeostasis of our body and keeping it where we want to keep it at.

So, looking at a little biochemistry here. When we're talking about inorganic versus organic. Inorganic compounds do not contain carbon with hydrogen bonded to it.

Organic compounds do contain carbon. with hydrogen bonding. So for example, if we're looking at inorganic, water is always a real good example. So water is H2O.

It's an oxygen with two hydrogens. There's no carbon there. We're going to see the same thing with our acids, bases, and salts. You don't have that carbon-hydrogen bond going on.

Water is a universal solvent in our body, which means it's really good at pulling things apart. So we looked at this when we looked at our polar covalent bonds. It has a positive in and a negative in.

Water has that big oxygen that pulls those electrons. stronger towards it, which makes it negative, and then the two smaller hydrogens that end up being positive because it's having those negatives pulled away from them. So since you have a positive and negative in, it's really good to attaching to things that are positive and attaching to things that are negative and actually pulling them apart so they actually dissolve in that fluid.

So in our blood, there's a ton of water. If you look at the breakdown of whole blood, about 50%, or a little bit better usually, is going to be plasma. Plasma is 90%, at least, usually more than 90%, just water.

So there's a high water content even in our blood. Digestive tract, there's also going to be a lot of water. It helps to break things down. Whenever we're looking at catabolic reactions, water plays a big role in actually breaking. those different substances down.

So even though water is a really good solvent at breaking things apart, it can only break things apart that are hydrophilic. So philic means loving, hydro means water. So things that are hydrophilic like water. Basically what this means you need a positive charge and a negative charge so the water since it's polar can grab onto both ends and pull it apart. So water is really good at dissolving or being a solvent for other polar molecules.

So here in the example, we have sodium chloride in example A. So sodium chloride, we saw sodium. This is going to be an ionic bond for our salt, sodium chloride.

The sodium has a positive end. Chloride ends up being negative. It's polar. Water is really good at breaking apart salt.

Put salt in water, stir it up, it completely dissolves, completely breaks apart. Second example to give, carbon monoxide. You have a carbon and an oxygen. Carbon's positive, oxygen ends up negative. Really good at pulling that apart.

So the big kind of rule here, like dissolves like. So one polar molecule will be really good at dissolving another polar model. Specifically water is what we're talking about most of the time. On the opposite hand, if something is hydrophobic, phobic is fear, hydro is water, has a fear or dislike of water.

Oils are always our classic examples. Oils and fats and we see this in cooking all the time. If you take an oil and pull it, pour it in water and stir it up, It might break into smaller droplets, but it doesn't completely dissolve like a salt would or like glucose would. So that tells us that oil is going to be nonpolar.

It doesn't have a positive and negative end. Most oils and fats are usually negative all the way around them or neutral. If you don't have those positive and negative ends, then that water can't bind to it and pull it apart.

All right, looking at our acids and bases now. So we're still kind of going to start with a base of water, but so water is H2O. So you got two hydrogens and one oxygen.

What we can do, we can break one hydrogen off and we end up with one oxygen and hydrogen still bound to each other. This is basically what we're looking at when we're looking at our acids and our bases. If we have more hydrogens just free-floating in our system, it actually makes us more acidic.

If we have more of the OH, or hydroxide ions, which is our oxygen and hydrogen still bound to each other, then we actually have more base in our system, or we become more alkalinic. It's basically just another term for base, and that's what we use in the body. We say we become more alkalinic. So when we're looking at acid and bases, it's really looking at how many hydrogens do we have versus how many hydroxide or OH negative ions do we have. Our body, when we actually break down nutrients to make energy or ATP, ATP is going to be what we use for energy, a byproduct of that is actually using hydrogen ions to make that ATP.

So we do end up with just by making energy extra hydrogen ions floating around in our system. Now we do have ways to neutralize that which is going to be with our buffer systems that can actually grab on extra hydrogens. Sometimes we combine it with hydroxide and make water, but there's going to be a point where we actually are making more hydrogens than we can handle, or then we have bases or are able to make water fast enough to contain all those hydrogens. So those hydrogen ions build up in our system and we have to have a way to get rid of those extra acids in there.

So this diagram is basically just showing you that if you start with water that can disassociate or break up into hydrogen ions to make acids or hydroxide ions to make those bases. So other molecules can actually grab some of those loose hydrogens and they can also grab some of the loose hydroxide ions. So when that happens, this is where we get our different acids and bases from.

Basically, acid has a potential to release a hydrogen. Base has a potential to release a hydroxide or OH negative. pH scale.

So when we're trying to measure our acid versus our base, we measure pH. So pH has a range of 0 to 14. All this is really looking at is the concentration of hydrogen ions. As you get closer to zero, it means you have a lot more hydrogen. As you get closer to 14, you have less hydrogen and more hydroxide or OH-ions. So here's a really good chart kind of showing you that. So pH of 7 is completely neutral.

We have the same number of hydrogen as we do hydroxide, and that's what these bar graphs are kind of showing here. So blood, pure water, milk is usually pretty close to 7. Pure water is right at 7. Blood likes to sit, we like to keep blood at about 7.4. We actually keep it just a little alkalinic because we want it to be neutral.

We don't want it to be too acidic. We don't want it to be too basic. As we start getting closer to the zero, here we can see coffee, tomatoes, then we go vinegar, lemon juice, to stomach acid, you increase the number of hydrogen ions.

But if you look at hydroxide, there's less and less. So that's why our pH scale is really looking at the number of hydrogen ions. The more loose floating hydrogen ions you have, the more acidic you become. If we go the opposite direction, things like baking soda, ammonia, bleach, these have more hydroxide ion. So, and less hydrogen ion.

So the more hydroxide you have, the more basic or alkalinic you're going to become. Buffer systems. So remember, buffer systems buffer the pH. They try and keep it neutral.

We do have some three really big buffer systems in the body. We have a carbonic acid or hydroxide carbonic acid buffer system, protein buffer system, and then a phosphate buffer system. You look at those a lot more in physiology.

when you really get into acid-base homeostasis. But those are going to be the three main ones we're really going to look at. What they're trying to do, they're trying to keep everything neutral. Most of the time, we're looking at pH of the blood. So blood should have a pH of 7.35 to 7.45.

Salts and electrolytes. So electrolytes are really important here again to maintaining the homeostasis in the body. Especially with our nervous system and sending signals throughout the body.

When you do look at how the nervous system sends signals, here again mainly in physiology is where you're going to look at the most. You're going to need the different electrolytes in certain concentrations so our body can create electrical signals. We actually create electricity by manipulating the different electrolytes in our body.

So a good example of electrolyte is sodium chloride, is that salt. So you have one in positive, one in negative, you put it in water, they get pulled apart. So then you have positive sodiums and you're going to have negative chlorides. If you split those apart and you have a whole bunch of positives in one area and a whole bunch of negatives in another, you kind of just set up the potential to make a battery. Battery has a positive in and a negative in.

You can create a charge and that charge can move through the back. That's what we're going to do with our cells. We're going to take the sodium. basically pile it up on the outside of the cell and take the chloride and keep it inside the cell or more commonly it's potassium sodium is on the outside potassium is on the inside and then we have a whole bunch of negative proteins that are going to be on the inside of a cell to using the sodium potassium chloride and those negative proteins we can actually end up making a positive area and a negative area And our cells are basically set up like tiny batteries, so they can actually create electrical charge. There again, that's going to be something you look at a lot more in physiology.

This is just giving you a little introduction to it. Now we're going to look at our organic compounds. So these are going to be compounds that contain those carbon-hydrogen bonds.

So our main ones in the body, carbohydrates, lipids, proteins, and then our nucleic acids or nucleotides. Now these can all come in monomers or polymers. If it's a monomer, it's a single unit.

But we can put these together to make polymers or to make bigger units if we're going to store them in the bottle. So the way we do this is by dehydration synthesis. If you dehydrate something, you pull the water out.

Well, if we pull the water out, we can combine these different subunits together to make long. chains. On the opposite end, if we want to break them apart and actually use them for energy, we can use hydrolysis. You put the water back in, it breaks the bonds and you end up with those smaller subunits that we can then use to make ATP or make energy out of. So looking at our carbohydrates, things that we usually think of as carbohydrates, breads, potato chips, french fries, These are carbohydrates.

This is going to be the main energy source for the body, is going to be our carbohydrates. Now, monosaccharides are usually three to seven carbon chains long. I'm not too terribly concerned that you memorize that. That's more of a chemistry thing. But just know a monosaccharide is basically one unit.

If it's a polysaccharide, poly means many, it's going to be a lot of these units actually linked together. But some examples of monosaccharide, glucose. Glucose is a carbohydrate. It's a monosaccharide. Fructose, which is basically the mirror image of glucose, we find that actually in fruits.

It's the glucose that we find in fruits. It's what makes fruits sweet. So there's a lot of different variations of monosaccharides. Galactose, ribose, deoxyribose.

These are all just different forms of a monosaccharide. So here's just showing you the different forms. Here again, I don't necessarily care that you memorize the different forms.

You're not gonna have to name them or anything like that. I just wanted to give you some examples of them. Now if we want to put these together to eventually make a polysaccharide.

So here we start with glucose and fructose. These are both monosaccharides. If we want to bond these together, We go through dehydration synthesis, which is this top arrow. We take the water out, you dehydrate it, and you can actually link these together. And now it's a disaccharide.

You have two units linked. Di means two. If you added a third, then that's where you're going to get your polysaccharide.

Or, if you want to break it down, you can go through hydrolysis, which is this bottom arrow. Put the water back in, break them apart. and then you have your fructose and your glucose again.

So we can build stuff up, we can break it down. Usually if we're building it up we're going to be storing it so we can use it later. If we're breaking it down we're usually breaking it down so we can use it for energy.

So like I said polysaccharide is just combining multiple of these mono disaccharides together to make nice long chains. With our carbohydrates, especially glucose, the way that we store it mainly in the body is as glycogen. We store a ton of glycogen in the muscle. We store a lot in our liver.

Since this is the main form of energy in the body, we need a ton of energy for our muscles. In order to be able to move, we need to be able to break small monosaccharides off of that big long polysaccharide chain. So we store it as glycogen.

And this just kind of shows you a little pic picture of glycogen. All this is is glucose Combine together in nice big long chains. We can store it and then use it as we need it. Lipids. So lipids actually can make a lot more energy than glucose or carbohydrates can because they're a lot bigger molecule.

However, it takes a lot more energy to break these down. Remember glucose? If you put sugar in water and stir it up, it completely dissolves.

That's because glucose is going to be a polar molecule. It has positive ends and negative ends. Lipids don't do that. They don't completely dissolve.

So they're going to be a non-polar molecule. We can still break them apart and use them for energy, and we do all the time. It's just a lot harder to do that.

That's why the carbohydrate is our main source of energy, even though we can actually get more energy out of lipids just because they're so much larger. So here's a picture of a saturated lipid and you hear a lot about saturated versus unsaturated lipids a lot. A saturated lipid has a row of carbons and every single carbon is completely full with hydrogens attached to it. That's why it's called saturated. This is a solid At room temperature, there's no double bonds.

It has the maximum number of hydrogen bonds. Here, this is a monosaturated or unsaturated. Sometimes, a lot of times, just in the food world, it's an unsaturated fat.

We kind of like unsaturated fats better because these are liquid at room temperature, and they're a little easier to break apart because they... have a double bond, it makes a little kink in the molecule. That little kink, since it's not completely saturated with hydrogens, actually makes it easier to break into two separate chains.

That's why a lot of foods will be labeled unsaturated or unsaturated fats. It's actually easier for our body to handle than the saturated fats are. So a lot of foods anymore have unsaturated fats in them. And here's just another one. So this is polyunsaturated.

It has multiple double chains. The more double bonds you can get, the more areas that we can break it apart and the easier it is to break apart. So this is what we generally see in a lot of the foods we eat now.

So here's a triglyceride. It's basically just a variation of what we just looked at. So it has a glycerol head and three fatty acid tells attached to it.

So triglycerides Whenever we're doing a cholesterol panel, we measure triglycerides. Triglycerides are basically three fats attached to a glycerol. These are relatively large molecules, and they can clog up our arteries, leading to things like heart attacks. So we don't want those triglyceride levels to be really high, because they cause a lot of problems.

They have a lot of potential energy in them, but too many of them can be a really bad thing. So there are all different kinds of lipids. So phospholipids, we need lipids.

We need fat in our diet. When we look at how our cells are put together, all our cells have a biphospholipid membrane to it. Keeps everything on the inside we want in the inside and everything on the outside that we want to keep on the outside.

So we have to have lipids in our diet just to maintain the health of our cells. Now here's a phospholipid. All of our phospholipids have a phosphate head and they have two fatty tails to them.

This is going to be a molecule that has a polar head and then nonpolar tails. It makes for a really good watertight barrier. Like I said, we're going to look at this more when we look at cell structure and how... These actually make up that cell membrane, but just another type of lipid is basically what this is.

So steroids are also a type of lipid. Cholesterol is a type of lipid. These sometimes aren't necessarily always. They don't have to be always chains or tells of fatty acids. They can make up what's called a four-ring hydrocarbon structure.

Basically, it just makes up a ring. So we see that in our steroids. A lot of our cholesterol. will also be formed that way and when we look at the liver we'll look at how cholesterol is processed and basically how we take fats and turn it into cholesterol we need that cholesterol in our system there again to maintain basically just those cells so there's a lot of different forms a lot of very different variations of our lipids also next up are proteins proteins are everywhere in the body almost everything is made up of a protein somehow, some way.

Enzymes are made up of proteins. All of our cells are made up of different proteins. Our immunoglobulins that we're going to use in our immune system are made of proteins.

We can break proteins down and use them for energy. Proteins are just everywhere. We're going to use them as buffers. Proteins can grab hydrogen ions and actually buffer our pH. So proteins are just absolutely everywhere in the body. We have 20 different amino acids that can be linked together.

When these amino acids are linked together, they're linked together by what's called a peptide bond. So we actually form polypeptides when we link multiple amino acids together. And then these polypeptides, these are what are actually our proteins, or what we refer to as a protein. So since we have 20 of them, we can put these together in a lot of different combinations. That's why there's so many different functions for proteins, and we find them throughout the entire body doing so many different things.

Because there are so many different combinations that we can combine these into, and then they have different functions depending on how we put them together in those different ways. So here again, we still put them together the same way we did whenever we looked at our glucose or carbohydrates. Lipids can do the same way. We didn't look at them in this sense. But we can actually link those lipids together, store them as fat, or break them down still using dehydration synthesis or hydrolysis.

So here we have alanine and glycine, which are two different amino acids. If we go through dehydration synthesis, which is our top arrow, we take the water out, we link the carbon and nitrogen together through a peptide bond. We now have a dipeptide.

If we want to break them apart, we look at the bottom arrow, go through hydrolysis, put the water back in, and now we have lysine and alanine, two amino acids again. So we can store it or we can break it down. So dipeptide, we just looked at, it's basically just two connected together.

You can also have a tripeptide, which is three, or polypeptide gets into 10 or more amino acids. These are making up our proteins. So a protein consists of one or more polypeptide chain.

So it's just chain of those amino acids put together, depending on how they're put together, is going to determine their function. and we're going to see that over and over again in the entire body. How something is put together, the structure of it, is going to determine its function in the actual body.

If a muscle wasn't put together a certain way, we wouldn't be able to move, it wouldn't be able to contract, and we wouldn't be able to get around. If a nerve could send electrical signals if it wasn't put together that way, we wouldn't be able to feel temperature changes or feel pain. So how something is made, how it's put together, is going to determine its function.

So just like we saw with our carbohydrates, with our lipids, there's a bunch of different types of protein. You can have fibrous proteins, you can have globular proteins. Fibrous proteins tend to make up fibers.

Globular proteins are globs. And we're going to look at a couple different examples of each one. Proteins become more and more complex with their structure and we have a way to organize these. And that's what the next slide is actually going to show.

So when we're looking at protein structure it kind of builds on itself. So here you can see we're going to start with primary protein structure. Primary structure is just a chain of amino acids forming a polypeptide.

That's it. A straight chain is primary structure. Secondary structure Those chains can form what's called a beta-pleated sheet or an alpha helix.

This becomes important because an alpha helix is actually what makes up our DNA. A beta-pleated sheet, if you think about taking a piece of paper and folding it multiple times on itself and kind of making an accordion type thing with it, that's a beta-pleated sheet. So those are the two forms.

that proteins can take if they're in secondary structure. Now, if you go up to tertiary structure, which is this third one, this is when you get into your globular proteins and your fibrous proteins. Basically, all you're doing, you're taking multiple beta-pleated sheets and alpha helixes, putting them together, and either making a globular protein or a fibrous protein. Quaternary structure. Quaternary structure is where we're going to have multiple globular proteins, multiple fibrous proteins, all intermingling with each other and all working together.

When we look at hemoglobin in the blood, it's a globular protein. Hemoglobin carries oxygen. It really is what makes our red blood cells red blood cells. And that hemoglobin is just a type of protein that is made to actually bind oxygen and move it through the body.

Like I said, proteins, ton of different functions throughout the entire body. We're going to find them everywhere. Proteins can be kind of fragile sometimes. They go through what's called denaturization.

The main things that will cause this denaturization is basically just a breakdown. It causes the proteins to break down. pH changes and temperature changes.

are going to be the two main things that really cause this in the body. This is why we have to make sure our temperatures don't get too much above 104 degrees Fahrenheit. Once you get above 104, you get into 105, 106, those proteins start to break down. Well, proteins are making up almost all the cells in our body. Our blood has hemoglobin in it.

It's a protein. All of our cells are going to have different proteins. proteins in them.

If that temperature gets to 105, 106, and those proteins start to break down, that means the cells start to break down and start to die. And the worst part, the proteins that are affected first are actually proteins that are found in our brain. So if those proteins start to break down in our brain, the brain's controlling everything else.

It's just kind of a domino effect from there on out. So... Really have to watch that temperature, but pH changes.

If our body becomes too acidic, then it also starts to break down those proteins. So we really want to make sure we stay in that homeostatic range. All right, last but not least is going to be our nucleotides.

So nucleotides are going to be a nucleic acid. I, their name because they're found in the. nuclei of the cells or the nucleus of the cells, that's why they're called nucleotides, this is what's going to really make up the majority of our DNA and our RNA will be these nucleotides. So a nucleotide has a nitrogen base, it's formed in a hydrocarbon ring, five carbon pentose sugar, and then a phosphate group.

And here this isn't something again that you need to memorize. But you can see a little picture of it. You have the nitrogen base, you have a pentose or a five carbon ring sugar, and then you got a phosphate.

That's what's making up that nucleic acid or nucleotide. Now with our nucleotides, we only have five different nucleotides. So we don't have 20 like you did with the proteins. These can be broken down into groups. You have your purines and then your primidines.

Purines are adenine and guanine and we usually abbreviate those with an A for adenine and G for guanine. Primidines are cytosine, uracil, and thymine. Now, here again we just abbreviate those with their first letters, so cytosine C, uracil U, and thymine T.

The reason why we break these into groups is basically just based on their structure. These have very specific pairing patterns that goes with In our DNA, we only find adenine, guanine, cytosine, and thymine. Adenine will always pair up with thymine, so A's always goes with T's, and guanine will always pair with cytosines, or G's always goes with C's. Uracil is only found in RNA.

It actually takes the place of our thymine. You don't find thymine in RNA. So we have the same pairing patterns. Guanine still matches with cytosine in RNA. But now adenine will match up with uracil in RNA because it took the place of thymine.

Another area other than just our DNA where we see these is actually when we make energy in the body. Adenosine triphosphate is one of those... adenines we just talked about with three phosphate molecules attached to it. Now you can't have just one phosphate or two phosphates or three. So if it's just one phosphate it's adenosine monophosphate.

When you attach the second one it becomes adenosine diphosphate and then when you attach the third one it becomes adenosine triphosphate. We abbreviate these. Adenosine monophosphate is AMP. Adenosine diphosphate is ADP.

Adenosine triphosphate is ATP. ATP is what we use as energy in the body. The reason why we say this is what we use for the energy is because we're going to store energy in bonds. So the more phosphate you add to it, the more bonds you create. When you break that bond...

it's going to release the energy. And a lot of times when we say energy, we kind of mean heat in the body. So a lot of times it's going to release the energy or the heat, and then we can use that heat to speed up chemical reactions.

Because remember, the higher the temperature, the faster a chemical reaction can occur. That's going to be work in the body, actually creating those chemical reactions. This is just showing you that the energy is stored in those bonds. So when we do add those phosphates, we're actually storing energy in the bond.

When we break the bond or break those phosphates off, the energy is actually coming out. So that's where that energy is really coming. Here's our DNA. So we talked about DNA in that first nucleotide nucleic acid slide. This is where all of our genes or instructions are written.

Basically how to make everything in the body. All of our proteins, all of our cells, all the instructions are stored in these nucleic acids and basically the different pattern that they're going to be arranged in. When we are looking at the DNA, we have that pentose sugar, we have that phosphate group, and then we're going to have our nucleic acids. So we have our adenine, our guanine, our cytosine, and our thymine when we're looking at DNA pairing together.

So like I said before, these have very specific pairing patterns, and that's what this is showing, right? So we have this double helix that wraps around each other, and if you look at the pattern going down it, if you start at the top, G pairs with C. T pairs with A, C pairs with G, T pairs with A. Your A's and T's always go together, your C's and G's always go together. Now depending on the pattern that they're actually pairing up all the way down here.

So here you have a G, a T, a C, a T, a C, an A. That's kind of making up its own alphabet going all the way down. Those are instructions on that particular piece of DNA coding. on how to make an amino acid. Those amino acids are put together to make proteins.

Proteins will be put together to make basically all different parts of our cells. So literally the instructions are written in that DNA with those different letters. And here again this is just going over the pairing patterns with you. So A always goes with T, C always goes with C.

This is called complementary bass pairing is what it's called. So the A's complement the T's, the C's complement the G's. Like I said earlier, in RNA, you're only going to have uracil.

You don't have thiamine. Still works the same way, except you're replacing uracil with thiamine. So now A pairs with U, C will still pair with G.

Now RNA is actually going to be... used in a process called transcription and translation. This is what really codes for most of our proteins. What we're going to do, we're actually going to use this, and we're going to take it to a ribosome, which is going to be an organelle we talk about in the cells, and we're going to look at this process more when we do look at cells a little bit.

And this eventually is going to be responsible for making the proteins in our body, going through transcription and translation using this RNA. And here's just a picture of both our DNA and our RNA put side by side. We're still using the nucleic acids for both of these. The pairing is really similar, it's just we have uracil in our RNA and thiamine in our DNA.

Transcript for:Anatomy chapter 2 the chemistry of life

Transcript for:
Anatomy chapter 2 the chemistry of life