chapter two then so there are some elements of the human body that are uh very common I think it's important to know what those are these are the four most common carbon hydrogen oxygen nitrogen I'm not going to ask you what percentage they are but those are the four most common and what do you notice about those four compared uh when you think about what you had to read for class today carbon hydrogen oxygen nitrogen section 2.4 was about the different classifications of organic molecules that are going to be important for physiology correct so when you look at organic chemistry in organic molecules the major elements found in all organic molecules are carbon hydrogen oxygen and nitrogen and then we have lesser elements and then Trace elements as well as well I'm not too concerned about those but definitely those four are going to be important I am not going to ask you any questions about atomic structure and charge some of you had chemistry I know some of you are in chemistry with me right now I am teaching chemistry this semester all right so this is important I'm not like I said I'm not going to get into this and expect you to know this but when you talk about chemical bonds and forming bonds between atoms or elements to form molecules and compounds and macromolecules it has to do with atomic structure and the number of electrons and so on and so forth so you asked to read about bonding what were the three or four technically uh major types of chemical bonds that you read about so coent hydrogen bonds I ionic bonds nonent what's that nonent so when we look at coal bonds there's two types there's polar and non-polar calent so this is showing what on this slide what type of bonds this is ionic bonding you have a positive charged atom negatively charged atom and without getting into all the theory behind it as much as I love chemistry it has to do with how many electrons are in those atoms it's all about making the atom itself neutral or excuse me more stable and if you gain or lose electrons it changes the charge of that atom That's the basis of an ionic bond when we talk about ion I bonds and you've heard of the term electrolytes you go to the doctor they take your blood they measure electrolytes it's basically a measure of these ions in your blood uh calcium sodium magnesium pottassium uh you also have uh these over herebody know the difference between a cation and an anion if you remember from chemistry Ireland one's positively charged one's negative cat with a t with a plus is a positively charged ion and anion is negatively charged and we have both of those positive and negatively charged ions we spend time talking about phosphates pottassium sodium um bicarbonate ions not throughout the entire semester but at various times in their importance of physiology all right these are examples of coent Bond so by definition what is a coent bond with respect to what's happening and how these two atoms are joined together okay so in the case of Co valent bonds the electrons are being shared that's different from ionic bonds because in ionic bonds we say that electrons either donated or received from other atoms that's not what's happening here where do these electron what do these electrons do in an atom yeah I am going to talk about this aren't I what do electrons do in these atoms they orbit that nucleus it's not the nucleus of like a cell nucleus it's just this area where we find the protons and neutrons and those electrons are orbiting around it when we have these coent bonds they're sharing those electrons and they're both taking their time and orbiting in this case here orbiting around both of those this one down here this carbon dioxide molecule you got some that are kind of doing this figure eight and you got some that are doing this figure eight that would be uh in general calent Bond well what's the difference between a polar calent and non-polar calent as far as the electron sharing is concerned sort of so all electrons are negatively charged so non-polar coent there is um equal sharing of those electrons meaning that those electrons spend the same amount of time orbiting around their the respective nuclei of those atoms but with a polar coent bond that means that electrons spend more time sorry around one part of the molecule or one part of the an atom of that molecule it's like the higher this is not an ionic bond so no so so what we find is that in this this is a hydroxide here an oxygen and a hydrogen bonded together if we were to kind of split this in half we would see that the oxygen side has a slightly more negative charge than the hydrogen side and that's because the electrons spend more time orbiting around the oxygen than they do the hydrogen and that creates this polarity you probably had a little unit on electricity magnetism in high school in physics or middle school and you have the positive and negative poles of a magnet type of thing this is the same idea is that one side of that molecule is slightly positively charged and one side is slightly negatively charged and that plays a big role in the chemical and physical properties of that particular molecule when we look at non-polar calent these typically are not water soluble they do not dissolve in water they typically have a tendency to float on top of a solution whereas things that are polar coent typically will dissolve in a solution water as a molecule is a polar molecule and if you add something that is a polar molecule to water well then those can very easily mix but if you add something like olive oil which is pretty much all non-polar calent bonds that is not going to mix with that water because polar and non-polar don't mix this has a lot to do with how certain things can pass through a cell membrane and get into the cell if they are lipid soluble like the plasma membrane is made of phospho lipids you had to read about that um if something is soluble can dissolve in lipids and other non-polar things they can pass right through that phospholipid membrane but if it's charged or if it has polar calent bonds there has to be another way to get it into the cell because it can't pass through those phospholipids so that's why this is important to understand I could ask you question say this particular molecule easily passes through the phospholipid by layer which of these properties most likely describes why this molecule is able to do that because it's non-polar calent bonds and the phospholipids are that as well or have those types of bonds as well they should yeah so the they all saying goes like dissolves like so you should be able to mix other non-polar substances together uh and have them mix to a point now density does play a role as well in that situation but yes theoretically yes all right now hydrogen bonds this is not a true true bond in the sense of electrons are being shared or transferred this is I guess we could call it maybe a pseudo Bond it's temporary and it's simply an electrostatic Bond it is a temporary electrostatic attraction of the negative part of one molecule to the positive portion of another polar molecule when I was a kid we used to take balloons and rub them on her head and build up static electricity and you could stick it on the wall it was like this amazing magic trick when you're 5 years old that's the same idea is that you're creating charge on the balloon and then those charges are kind of realigning so that positive and negative are attracting that's what's happening uh with these hydrogen bonds e yes so when you look at DNA there's hydrogen bonds that keep the bases of that DNA together um there's other factors that keep it together but yes those bonds have to be kind of broken to open that up so that you can do your transcription making a copy for making proteins or replicating that DNA so I don't I don't want to say it makes it easy but those bonds are easier to break this happens a lot in like a say a beaker of water notice that these are water molecules and we can split those molecules kind of in half and that the hydrogen side of those molecules have a slightly positive charge that's what this little greek I think that's a gamma uh this lowercase gamma represents and then over here in the oxygen side it's negative because the electrons are spending more time around those electrons so that's a hydrogen bond not a true bond in the sense of ionic and coent but a bond nonetheless questions from 2.2 that maybe you had that didn't have a chance to submit them well seeing none let's move on to the next section I believe this is 2.3 I just want to briefly go over this idea of a solution not as an answer to a math problem but as uh essentially a mixture of different things and I like to look at this as an arithmetic problem the solute plus the solvent equals the solution typically water is a solvent if we look at biological systems inside of a cell inside of our blood it's all water-based and we can there's going to be things that are in that water solute so this is what is being dissolved in the solvent so if I said we had a sodium hydroxide solution or sodium chloride solution it's going to be sodium chloride plus water so you got a bottle of sodium chloride you got a beaker of water you mix the two and now you have a sodium chloride solution our blood for the most part is a solution there are things that are dissolved but there's also things that are suspended that's more of a what we call a colloid was that word mentioned in your book a colloid okay colloid is things that aren't dissolved but they're kind of equally distributed and suspended within that solution all right pH we do a whole Lab on ph and you'll be asked to come back and review this we look at buffers and buffer systems and simulate biological systems and cells and extracellular fluid to see how well they buffer certain Solutions don't memorize these values for what you need to know now at this point understand that the pH scale goes from 0 to 14 and P when we talk pH we're talking acidity there's also something called the PO which is a measure of the alkalinity we don't really use that in physiology it's pH but yeah no no no you will not have to calculate pH which is the negative log of the hydrogen ion concentrate if you took chemistry but so if I had a pH of one how would you describe the acidity compared to something with a pH of nine more acidic less acidic or equal more acidic so the smaller the number in the pH scale the more acidic and what are we really measuring when we measure the pH we're measuring what we call the hydrogen ion concentration and a hydrogen ion is a hydrogen atom that's positively charged let's look at that because this will be important next week when we start talking about oxidation reduction reactions in glycolysis and the citric acid cycle or the kreb cycle if you look at hydrogen it's got one proton and it has one electron in its orbital protons are positively charged electrons are negatively charged what would the overall charge of this hydrogen atom be those of you that had chemistry if I have a dollar but I owe someone a dollar and I give them that dollar now I have zero money same idea negative 1 plus a positive one equals zero therefore this is neutral it has no charge but there are a lot of instances where this electron goes away and we're just left with the single proton that is a hyro ion it's also called a proton because really that's what it is so when we talk about pH and acidity we're talking about how many hydrogen ions we have and when we look at the pH scale it's a relative scale a pH of four is more acidic than a pH of five a pH of nine is more acidic than a pH of 10 by what amount is a pH of four more acidic than a pH of five 10 times it's what we call logarithmic scale it's based on tens you heard of the RoR scale for earthquakes same thing a magnitude nine earthquake is 10 times more powerful than a magnitude 8 earthquake same idea don't memorize these numbers here I think it's important to know that pure water has a pH of seven it's completely neutral it has an equal amount of hydrogen ions and an equal amount of hydroxide ions let's fill out this table what we want to do is compare and contrast organic molecules with inorganic molecules and I'm going to get you working on something in groups so you don't have to listen to me talk the entire hour I think it's important that you understand the differences between things that we would consider organic molecules and things that we would consider inorganic molecules so let's look at organic molecules and kind of create a classification system to compare so let's start with Organic mainly what we're seeing with Organic is it's hydrogen bonded to carbon doesn't mean you can't have hydrogens and carbons in inorganic but mainly the majority of the atoms we're seeing in organic molecules are going to be carbon hydrogen have carbon hydrogen bonds coal bonded organic molecule are covalently bonded some are non-polar calent some are polar calent most lipids are going to be non-polar calent some have both properties and both characteristics like phospho lipids what was the term we used to describe the fact that phospholipids have kind of polar and non-polar properties and it affects their relationship to water what amp empathic yes correct they have both polar and non-polar characteristics they're both water fearing and water loving um organic molecules are said to be non electrolytic is that red color okay or should I use a different color let me know I'm sure there's [Music] some what this means is that when you put organic molecules in water they don't break down into their component parts but if you put sodium chloride in water that sodium chloride is going to break uh up into that water as sodium ions and chloride ions surrounded by water molecules those are those electrolytes sodium and chlorine electrolytes organic molecules are not electrolytic don't they do not dissociate in water now relative to inorganic molecules organic mole molecules are very large composed of many atoms could be hundreds maybe thousands depending on what the molecule is if it's a really complex molecule and the last one organic molecules are the major component of living things now I am not going to go over this column right now here's what I want you to do in little groups small groups I want you to fill this out and this is what I'm going to tell you this is the hint I'm going to give you for the most part inorganic molecules are kind of opposite of these characteristics for the most part I want you as groups to kind of discuss what you think you should put then in the corresponding cells here that make sense and then we'll go over that and I'll tell you about some exceptions to those general rules okay all right go ahead and do that take five minutes think about what we said about organic for the most part the inorganic are going to be opposite you don't need to Google anything look at the information I've given you let's see what we came up with so what do you think we should write down for inorganic molecules as far as these bonds go and bonding first one hydrogen bonded to carbon so in organic there's I guess we could say there's very little carbon not saying that there isn't carbon but there's very little carbon and we can also say there's very little hydrogen so when you look at the hydrogen's bonded to carbon there's not a lot of that there are molecules that have carbon in them that are considered inorganic for example carbon dioxide it's got carbon it's got coent bonds but it's very small and it is not organic one of the other characteristics of a lot of organic molecules is that they burn you can't burn carbon dioxide all right inorganic what types of bonds do you think inorganic molecules have I most inorganic molecules are ionically bonded give me a couple of exceptions carbon dioxide and probably one of the most prevalent molecules on Earth and in our bodies huh water H2O that is Cove valent bonds but it's considered inorganic so Exceptions there what happens if you put something like sodium chloride into water it dissociates okay so they're considered to be electrolytic and theoretically I suppose if you put a couple of wires in there you could conduct charge between those cathodes and anodes to create electric current next one if organic are very large molecules with many atoms what about inorganic they're typically very small with many fewer atoms and then as far as being a major component of living things organic molecules inorganic very small percentage except for what water always exceptions scientists love to categorize but there's always these little exceptions here and there questions about any of that take a look at page nine through 12 in your packet 9 through 12 so what this is this is called a pogil it stands for process oriented guided inquiry learning you read the description the information there it provides you some background and then you do the questions so it's kind of some guided learning but I think this is something that may help you understand a little bit more deeply some more of the things that were uh in in the reading for Section 2.4 so in groups I'd like you to work on pages 9 through 12 do not do any anything with enzymes if you get done with well proteins move on to nucleic acids which starts on 13 do not do the enzymes we're actually going to take a look at that next week Tuesday so leave that one blank so work in some groups discuss the questions make sure everybody kind of comes to a consensus and make sure everybody understands what's going on I do a lot of group work I prefer that you work in groups and not work alone so if you need to move your chairs around to the other sides you're having conversations I'm totally fine with that I want to interrupt a minute take a look up here I'm going to go over a few things in your packet as well with the last five minutes so this is on the last slide in your chapter two part of the packet organic molecules consist of a carbon backbone meaning that there could be multiple carbons bonded together which is kind of what you're seeing looking at these reactions and looking at these disaccharides except in those cases they're kind of all linked like this and then there's another carbon somewhere else so there's an oxygen there same idea except this is just a ringed structure but there are what we call functional groups a hydroxy group is an O A methyl group is a ch3 so a carbon with three oxygens a carboxy group amino group and phosphates I'm not asking you to memorize all those some of them you will see and have already seen like the amino group and phosphates when you write these formulas and really this is the only time you're going to do that it's carbon first hydrogen and then oxygen and we know C6 h206 typically it's going to be represent glucose but what did you learn well sucrose and lactose and maltose all have the same uh molecular formula what about glucose are there other things that have C6 h206 that are not glucose there are okay those are called isomers when you look at maltose maltose is C6 h126 plus another glucose oops I'm going to wait to write that out what did we call this reaction to synthesize this molecule maltose we had to remove a water molecule that is called dehydration synthesis dehydration meaning removal of water synthesis to create something new so if we removed a water molecule by joining these two together without even looking at the structural picture you should be able to figure out what the uh molecular formula is how would you calculate that so add up all the number of carbons all the number of hydrogens and all the number of oxygens that you get from the two glucose we'll do this in Step One h two steps so you double that you get C12 h242 but that's not maltose we had to remove a water molecule so we have to subtract two hydrogens and one oxygen from that and we get C12 H22 o1 that is the oops that is the uh molecular formula for maltose lactose and sucrose they're just shaped differently those functional groups are in different spots that's why they're different it also means that lactose is made up of not two glucose but a glucose and something else and sucrose which is normal table sugar is is also made up of two monosaccharides I'm not going to ask you that on the test because I don't even know it not that important to know but okay how would you describe a hydrolysis reaction think of the meaning of the prefix and the root hydrolysis Hydro meaning water lces to lice something would be like a cell lces it breaks apart right so if you were to write that in a sentence we could say if we said dehydration synthesis is removing water to create something new hydrolysis would be adding water to to break something apart okay and that's how a lot of these organic molecules that we're going to talk about through the semester are synthesized and broken down metabolic reactions catabolic would be a reaction where things are being broken down into its component parts anabolic are reactions where things are being added together to make something new and metabolism and all these chemical reactions occurring in the body a lot of them are just these reactions back and forth next week in chapter 3 we're going to start talking about enzymes and receptors and the role they play and metabolic and chemical reactions um these things that we've just looked at the hydrolysis and dehydration synthesis require enzymes they don't just happen naturally there has to be something that facilitates the release of that water or the addition of that water and we'll address those next week week what I'd like you to have done for Tuesday there will be a link to upload a PDF of this is I'd like you to finish everything on this packet except for enzymes okay do your best I'll answer questions I'll also post an answer key so you make a valiant attempt to complete this right or wrong you'll get full credit I will post an answer key and answer questions next next week