Biology 2010 Course Overview and Chemistry Basics

on this computer. And good morning to everyone. Welcome to the Zoom. So again, if you're new to the class, my name is Pam Thomas. This is Biology 2010. Okay, so first order of business, a couple announcements. And I've said this before, but I'll say it again. There are still 520 students that have not gotten their lab together. You know, you need to purchase the universal, you need to get the icon, you need to download the icon. There's all kinds of directions in the lab web courses. Lab is not in web courses or Canvas. It's not in Zoom. It's in universal. There are labs this week. So this week at your lab, day and time that you're registered for, you will go into the lab. There's one exception to this, that's if you have lab one Thursday between 2 and 5 30. UCF has a football day on Thursday, so the university closes at 2 p.m. Michelle Yergin is the master lab professor over all the lab teaching assistants. She will post a message in your lab web courses that If you have lab one Thursday, usually she'll give you access throughout the whole week to do it at any time. But she will post that announcement. It's probably already there. So you want to look for that if you're a Thursday lab that's affected by the football. Okay. So today we're actually going to start to do a little bit of biology. And we're actually going to do some chemistry. These are jellyfish. They're kind of pretty ones. And they have certainly a lot of chemical defenses in their stingers. You know, everybody who's ever encountered a jellyfish and gotten stung knows that's not pleasant. You can neutralize it with sodium bicarbonate, actually. But you have to be careful because that pH is wrong for your skin. And so you have to be careful how you do that. So... We're going to be talking about the chemistry of life. For all you chemistry majors, this is going to be super basic stuff. We're not even going to go into a lot of things. We're going to get you just as far as we need to be to do cells. Some jellyfish are bioluminescent. This is due to the chemical called a quoran. When it binds with calcium, it lights up and it gives off this blue glow. And if you are fortunate enough to have been in certain parts of the Gulf of Mexico at night at certain times, the bioluminescent marine life start to make the water glow. It's called blue flash. It's really, really interesting. And in the Caribbean, in a lot of places, it's very intense. Around the Turks and Caicos Islands at night, some nights. You just see waves that are like fluorescent rolling in. It's really pretty interesting. And Cocoa Beach, yes, you can see it there too. Okay, so over 76% of marine animals have some kind of bioluminescence. It's not all based on a quorum. And we actually can use this bioluminescent chemical in lab experiments to help us light things up and show. if things are present. Okay, so life depends on chemical reactions. Matter takes up space and occupies mass. This is kind of like in your high physical science. There are actually more than 92 naturally occurring elements now, but we're going to say there's 92 that we're interested in. 25 of those are essential to life, and we're only going to talk about a few. that are really important in cells. And again, the PowerPoints are posted, so these major topics I'm hitting, you can already have those, and you just want to take little extra notes about what we're talking about. And I do have in the first module like sample notes for chapter two up so that you can see how to take notes if you're a first semester freshman and have never had to do it before. So Four major elements that you see in 96% of living things. Hydrogen, oxygen, carbon, and nitrogen. And we can actually turn this around into a memory device. A very big one. Memory devices. When I was in school, it was how I studied because I didn't want to spend a lot of time studying. So I turned everything in. Honk. Hydrogen, oxygen, nitrogen, carbon. Okay. Four major elements that are in a lot of things we're going to talk about in life. Alright, let's stop this. It's being fussy. I guess I'm going to have to erase it. Usually you could just clear, but they keep changing this all. Okay, I'm just going to stop that. So there are other elements, certainly. Phosphate, calcium. Sulfur, potassium. I mean, these are all also in cells. Potassium is really important in cells, but they're at much lower levels. Are both lectures at 9.30 and 10.30 the same? Yes. Okay, I see you, Andrea, at the end. So trace elements. are required in small amounts, things like zinc, for enzymes to work a lot of times. What is an element? An element can be broken down into any other substance by a chemical reaction. So it's like the atoms that are all together. Okay. Oops. So to show you what happens when living things are not too happy, you see this a lot in Florida. These little, you know, this is like a giant zamiya. It's a very ancient plant. Inside the leaves look like stained glass windows. It's incredible in there what the structure looks like. They're really pretty inside when you look at the leaf structure. This is a magnesium deficiency. Lots of people think when things turn yellow in the plant world it's an iron deficiency. This is a magnesium deficiency here. This is an iodine deficiency. And so with the iodine deficiency, that can lead to enlargement of the thyroid, which laymen call goiters. That can become a life-threatening situation. We don't see this a lot in the United States because if you look at your salt, it says this salt is... iodized. That means they've added just enough iodine to prevent this from happening to you. If you go to work for any of the, you know, World Health Organization, UNICEF, any of those, and you're working in other countries that don't have iodized salt, you will see this. So you all know what atoms are, but we're going to go over this. We're starting from the beginning because In Florida, lots of students have not had lots of different things. Different schools, even though they're supposed to be unified curriculum, don't cover certain things. So we want to make sure everybody has the basics. Atoms are made of protons. There are the positively charged particles in the nucleus. Neutrons, they're the non-charged particles in the nucleus. And electrons, these are the things on the orbitals that go around. They are negatively charged, right? Atomic number is related to the number of protons. Atomic mass or weight is the protons plus the neutrons in the nucleus. Now, there are orbitals and energy levels, and we are not going to get that far into this. We're not going to talk about... p3 and hybrid orbitals or any of that kind of stuff. That's what you're going to talk about in your chem class eventually. So the outermost orbital of every atom is called the valence shell. This valence shell, this outermost shell, those electrons are the ones that participate in the chemical reaction. Either they make sharing bonds or they transfer electrons back and forth. So the valence shell is very important in atoms because this is where the chemical reactivity occurs. Now, these words are really close. Valence denotes the bonding capacity of an atom. Valence by itself, not valence shell. Valence, this is how many electrons an atom needs to gain stability. So by itself, the word valence means how many electrons an atom needs to gain stability. This is a reflection of how many bonds it needs to make. to become stable and we're going to talk about what stability is. Okay valence electrons or valence shell electrons. This is the number of electrons in the outer valence shell that are existing. So valence shell electrons or valence electrons. How many are already there? It's how many are sitting parked in the outermost orbital. That's valence electrons or valential electrons. Valence by itself, how many you need to get to stability. And stability is defined by certain numbers of electrons, which we're going to talk about. Some people are saying, why didn't we do chapter one? Because chapter one is just everything. They try to tell you everything in biology in one chapter. which is totally useless. So your first exam will be on chapters 2, 3, and 4. We're not going to do chapter 1. So here you can see protons, the neutrons, and this is one valence shell with some electrons. This is hydrogen. Hydrogen is a tiny little atom. Okay, let's put this here. What is a cation? Cation is an atom that's ionized in a certain way. Cations lose electrons. They give them away. So they're in a negotiation trying to bond to satisfy stability, which we're going to talk about the octet rule. And they give away an electron, one or two or three or however many, in that process. When they give away an electron, they have less negative now and more positives in protons in the nucleus. A neutral atom has the same number of protons as it has electrons, and the pluses and minuses balance out, so there's no net charge. In cation, when you lose electrons, you get a positive net charge of some kind, plus one, plus two, plus three. In anion is an atom that has gained electrons. So in the negotiation to try to get stability in the chemical reaction, they gain electrons. They then have more negatively charged electrons in their outer shell than they have protons in there. nucleus and so they have a net negative charge questions yet you pause so do cations have a net positive charge because they give away that um yes and so you know basically i'm going to kind of so here's a little ad i'm Here's the nucleus. Let's say we had three protons here and we had three electrons out here. Let's say there was another one in here. There are two electrons here. This is what we're looking at. And let's say we have three protons. Let's say we give away two electrons. Now we have three positives in here and we only have one negative. This is going to have a plus two charge. Did that make sense? Yeah, because there's more protons than electrons. Other questions about anything? So the cation is like lose electrons to obtain like... Stability. We're going to talk about what the octet rule means and... how you get stability and what does that mean. Realize it is not something you have to install. Universal is what you need to install. Okay. Octet rule. Here we go. Octet rule is a rule that governs the chemical reactivity of atoms. So what they're doing with their outer orbital valence shell electrons. Are they giving them away? Taking them? Are they sharing them? Because they can do that. Are they sharing them equally? Are they sharing them unequally? You know, there's a lot to unpack here. So atoms react to get stable in their outermost shell, their valence shell. So there are big atoms. There are really big atoms, but we're not going to go there. We're not going to have big atoms. We're going to talk about carbon, hydrogen, oxygen, nitrogen. And these... have two rules. Okay, most of them will want to get eight electrons for stability. So however many they have, they're going to want to get eight. That may mean giving away electrons, taking electrons, or sharing electrons. Hydrogen is the exception. Hydrogen is this tiny little atom. It only has, this is the nucleus here. protons, here's the neutrons. It has, it can take a maximum of two electrons and it only has one shell. This is how it goes with atoms. If an atom is bigger, let's say we have two shells, the first orbital can only ever take two electrons. This is the nucleus. That's because the nucleus is like a cloud and it kind of gets in the way. with this first orbital. So you can only ever put a maximum of two electrons in the first orbital, okay, when you're, if you're running this out, and we will. And then you can have up to eight electrons out here. Hydrogen only has this first orbital. It doesn't have any more because it's a tiny atom. So it's the exception to the octet rule where two will give it stability. All the other atoms that we're going to talk about need to get to eight for stability, whether they give them, take them, the electrons, or they share them. And we'll be talking about that. Okay, it's irritating to have to keep doing that. All right, used to be able to just clear it. Okay, so all right. So here we're looking at oxygen. eight protons, eight neutrons, two electrons in the first orbital, six in the second orbital. It can take two more out here. Okay, to satisfy the actant rule it would typically, it depends what it's what what the how do you know if it's going to give electrons, take electrons, or share electrons. It depends where it is in the periodic table of elements. We are not going to ask you to memorize the periodic table of elements, thankfully. But some of these elements are very electronegative, and we're going to talk about that. So that showed oxygen. We're going to look at a little bit more about valence now. We want to know the valence of these. So how many electrons does hydrogen need? Usually it has one and it needs one. We're going to use the memory device. Honk, hydrogen one, oxygen needs two, nitrogen needs three to get stability, and carbon needs four. Honk one, two, three, four. Now you know the valence of hydrogen, oxygen, nitrogen, and carbon. And again, this is a reflection of the number of bonds they're going to make. And bonding is different with different elements. Like when two oxygens are together in the air, when you're breathing in oxygen, it's O2. That is called a nonpolar covalent bond. And we're going to see this. Nonpolar covalent bonds, there's absolutely equal sharing. So the two oxygen atoms back up next to each other. You get some electrons and then I get them and then you get them and then I get them and then you get them and then I get perfect sharing, equal sharing. Nobody hogs the electrons a greater percentage of the time. I'm going to have to, I used to be able to just clear this. They keep thinking they're making Zoom better, but they make it more cumbersome to use. Okay. All right. So if in Adam. I have a question. Yes, go ahead. About the valence. So there's six on the outside. You said the valence is two because the ones in the middle shell have to go to the outside. And that's why the valence is two. Okay. So. Let's draw this. So this is the nucleus. These here never do anything. They can't go anywhere. They can't do anything because there's another shell outside of here. This is the valence shell out here. Valence shell electrons. There's six out here. You have to add two more out here. Nothing can happen here. They literally, so they would like come to another oxygen atom. If it's the air. And they would literally start sharing the electrons to get, you would get eight for a while and I would get eight for a while. Does that help a little bit? Yeah, I suppose. Okay, we're gonna, we're gonna keep talking. On the slide before that, you said the number of electrons is a reflection of the bonds. Yes, so. You know, basically, when you add two electrons, it means you have to bond in some way to another atom to be able to either share them or sometimes, ionically, you rip them off. And we're going to see examples of this. So if an atom has six total electrons, here's the nucleus, you would have two in the first shell. and 4 in the second. That's 6 total. Not 6 valence shell, 6 total. This is carbon. If an atom has a charge of negative 1, it's an anion, negatively charged ion. The first orbital from the nucleus only ever holds 2 electrons. If an atom has 7 total electrons, there's the nucleus, two in the first orbital and five in the second orbital. It needs three out here to get to stability. This is nitrogen. Nitrogen needs three, has five. This is, I know if you've never seen this before, you're probably thinking, OMG, but it will get better. You know, We're not going to do chemistry forever, which is really good. And the good news is your final is not comprehensive. So as you get through each test, you're making it through and getting along. Okay, and so here are all the answers. Bonding. So let's talk about this sharing or this giving of electrons. There's three major types of bonds. It's really important that you understand this. So if you read it and you study it and you're confused, this is why we're going to have Andrea, your SI leader, talk a little bit soon about SI sessions, help sessions. Also, Anika, your TA has office hours. I have office hours today at 2. I may be a little bit late. I have meetings going on still. It's insane. It's the first couple weeks of class, but I'll be there eventually. Your other TA, Kayla, has lots of office hours. The office hours are all posted in the syllabus. And Andrea is going to talk about hers in a little bit. So electrons are shared in covalent bonds. Polar covalent bonds is unequal sharing. Non-polar covalent bonds are equal sharing. I'm going to say that. The non-polar covalent is... equal sharing, like with hydrogens or oxygens. The two elements, the two atoms have the same pull, and so they're sharing absolutely equally. But there can be also these non-polar covalent, where one atom is a bigger electron hogger than the other atom in the pairing. And so the bigger, stronger atom hogs the electrons. a higher percentage of the time. It's sharing. They don't rip them off. They hold them longer. When the atom that is bigger and stronger... holds electrons longer and then finally gives them a little bit to the other element, it's called electronegative. Electron-hogging elements are electronegative. They are typically found in row number seven in the periodic table. Fluorine, chlorine, bromine. Ah, they are so reactive that they will literally rip electrons off. And they will go ionic most of the time. Water is an example of some substances like hydrogen and oxygen that form polar covalent bonds. And we're going to show you this. So polar covalent bonds occur between molecules of a single atom. And we're going to indicate pluses and minuses. They're usually associated with partial charges forming, not full charges. It's not plus one, minus one. You see this squiggle sign. This is, then you'll see like four or three, or you'll see plus or minus. Most of the time you're going to see plus or minus. Partial charges happen because of this electron hogging electronegativity. Electronegativity is the tendency of an atom to pull and hold electrons, but not forever. It doesn't rip them off. It doesn't hold them and never give them back. It gives them back eventually for a partial time. So we're going to show you. Here is a water molecule, okay? There's oxygen. These are the hydrogens. Oxygen is big and it is an electron hogger, but it's not so much of a hog that's going to take the electrons and keep them. So in this sharing, if we look at this for 100 seconds, for 90 seconds, the oxygen would keep these electrons orbiting. It becomes partial, this is a partial sign, partially negative. The hydrogens, which are little and puny, it's like when you, if you're like ever pulled a rope, you know, in a game, and like there's too many people on one side, and they just pull and you go flying, the hydrogens don't have enough pull. So they do get the electrons once in a while. like maybe this one gets it for five seconds and this one gets so they become partially positive again this is not plus one minus one these are like partial charges okay and so here you can see it and these partial charges are attractive and hold the hydrogens to the oxygen okay questions about this Isn't water special because it can offer its valence electrons to form dative bonds, and that's also what makes it a good ligate? Yes, but first semester freshmen don't know that yet because they haven't had chemistry. You must be a chem major. Yes. No, I'm a biomed. I'm also a freshman. Okay. Oh, wow. So did you have like IB or something? No, I just did a little bit of learning outside of. Okay, that's cool. Yes, that's all correct. And everybody else, don't worry about what he just said. Okay, now we're going to switch to another kind of bonds, ionic bonds. This is where the electron hog is such an electron hogger. It's like so extreme that it backs up to the other atom and literally pulls the electrons out of the atom's orbital and steals them, literally. OK, this is ionic. This is where you get full charges like plus 1, minus 1. Literally, electrons are being moved permanently into other atomic orbitals, outer orbitals. This occurs, and you get the cations and the anions. OK, so we're going to do something here first because I want you to see this. We're going to look at table salt. Okay, so chlorine has 17 electrons. Now, I know I promised you we weren't going to do big ones, but this is a big one. This has three orbitals. There's the nucleus. We have two in the first one, eight maximum in the second one, and we have seven left over. Chlorine is incredibly reactive. It gets near other atoms and says, I just need one more. So I'm going to force you to react and I'm going to rip off the electron. And it does rip off the electron and then it takes eight and then it becomes negative one. This is why we get so excited if you get an accident with a train car full of chlorine gas, because it will react with your lung tissue, with everything. It's taken that electron. Like nobody has anything to say about it. Okay. It's extremely electronegative. This and fluorine are some of the most electronegative things in the world. And so they're very toxic to humans in certain forms. Now we use chlorine in our pool and diluted in order to kill germs and kill algae and stuff, which it fries really quickly. Okay, what is something with chlorine in it? Chloride, sodium chloride, table salt. This is an ionic bonded substance. Na sodium and Cl chlorine, NaCl. What you eat on your food. Let's look at how this works. Now we're going to see an ionic bond happen. think they messed up here. Let's see. We should have 1, 2, 3, 4, 5, 6, 7, 8. And here we have 1, 2, 3, 4, 5, 6, 7, 8. And here we have, there should be, yeah, this is your book sometimes. There should be another one right there. There we go. So here's sodium. Here's its valence shell electrons. There is not enough energy in the world for this to add seven to get to eight. So it wants to get rid of this one. It says, if I can just get rid of this one, I drop back to the second orbital where I already have eight and life is good and I have reached stability. Chlorine has seven and needs one. So sodium gets near chlorine. Chlorine says, give me. you're one now i have eight on my outermost valence shell i am happy okay and this is the valence of chlorine how many does it need it needs one to get stability it takes that one from sodium now chlorine's outer orbital is at eight it's happy sodium drops back to this orbital which is now the outermost orbital that's filled it has eight everybody's happy and we have table salt, which is what you use every day. This is an example of ionic bonding, and, okay, I have to do this again, the sodium becomes plus one, because there's now, this had like two, eight, and one it had 11 so this has 11 protons in the nucleus and this um basically what we do is we now have more protons and minus one electron is going to happen so this becomes a cation and this gets a negative one so this becomes an anion sodium is plus one chloride is negative one everybody's like omg oh clear all drawings that's what i want okay so questions about this so this is ionic bonding they literally rip them off from each other give them take them and they never go back where they were again they stay with those atoms okay And then there's Hydrogen bonding. Hydrogen bonding is so confusing for students a lot of times. Hydrogen bonds are between multiple water molecules, as an example. This is one example, and we're going to show you this. So, whereas polar covalent bonds were between... the atoms of a single molecule of water. Polar covalent bonds were between the atoms of a single molecule of water. Hydrogen bonds are like this attractive bonding glue that stick together multiple water molecules. So you're going to find hydrogen bonds between different water molecules. and we're going to show you. Okay, so I'm right again. Let me use a different color. What color do I want? So right here, this is a hydrogen. This is an oxygen. This is a hydrogen. It's like Mickey Mouse. These bonds are polar covalent right here. It's a P. This is a single water molecule. Polar covalent bonds, I'm saying it again, are between the atoms of a single molecule. In this example, a single water molecule. Okay, this becomes partially negative, which is hard to see here. These become partially positive. Now, what hydrogen bonds are is between the molecules. Here's a hydrogen bond. This. This. Here's a hydrogen bond. Here's a hydrogen bond. These are the hydrogen bonds between multiple water molecules holding the water together. What is the force holding them together? The partial negative here and the partial positive hydrogen here are attracted to each other like little magnets. And so partial positive here, partial negative here. You can see it in black here. So hydrogen bonds. Oh boy, my clock's going off. Sorry. Can you guys hear that? Okay, now it's done. So hydrogen bonds are between multiple water molecules holding them together, whereas polar covalent bonds are in each. Single water molecule, I'll do this in green now. In green, we have where the polar covalent is. In each individual water molecule, that's polar covalent. Between all the water molecules, hydrogen bonds. Questions about what we're saying here. This takes some time to look at. So if you've never had chemistry before, Don't panic. It takes a little while to get used to all of this. So the hydrogen bond holds together the like multiple molecules of water together. Yes. So it has it has a partial negative and a partial positive in the bond. OK, so what is happening is the oxygen. is partial negative the hydrogen is partial positive and so literally this is what's sticking the bond together like glue it's kind of like if you put opposite ends of the magnet together and you can feel the force that's what this is it is literally holding a glass of water all those the liquid water molecules are being held together by these hydrogen bonds that they don't come unglued does that help a little bit Thank you. Yes. Okay, good. All right. Other questions? Professor, someone asked, is polar equal or non-equal? Polar covalent is unequal. So let's look at this. So here, if we look at this, this one is the electronegative element. This is oxygen. It's a hogger. It's an electron hogger. So if we looked at this for 100 seconds of time, where is the electron at? Okay, to say it in vernacular, where does the electron reside most of the time? 90 seconds here. Whoever has the electron longer becomes partially negative. Here, we do share, but it's grossly unequal sharing. So we only get the electron for five seconds. We become partially positive. And this hydrogen, these are all hydrogens, only has it for five seconds, so it becomes partially positive also. That's why these are partially positive. So polar covalent is really unequal sharing. Yes, that it is sharing, but one of the electron hogging elements holds those electrons in their orbital for a really high amount of time and then gives them back for a little bit of time to the poor puny hydrogens. They're small atoms. They don't have pull. They can't fight back. Does that help? Let's just do this. Okay, so what is this? These bonds here, a single molecule of water. This is a polar covalent bond. This is another polar covalent bond. Between the water molecules, this is a hydrogen bond. And then I gave you the answer so that you can try this stuff. And here's just a picture. It's kind of blurry. All these polar covalent dot bonds. And then there's polar covalent and solid. And there's hydrogen bond in dotted lines. Okay. We're doing pretty well right now, which is good. So we're going to talk for a minute about isotopes. Isotopes. have different numbers of neutrons in the nucleus. So what you'll and a lot of they're not all radioactive. Many of them are radioactive but they're not all radioactive. A lot of times the radioactive isotopes, so you'll see carbon 12, carbon 14, different number of neutrons in the nucleus. Same element, different number of neutrons. That's what isotopes are. There are a lot of medical uses for the radioactive ones. I had to have, so I've had cancer like a couple of times. Two years ago was the last time. Different cancer both times. I'm good now. Thankfully, hopefully I'll stay good. But this is a PET scan. PET scans, I had to have one of those in February. They give you radioactive glucose. They check your glucose level first to make sure it's low, it's normal. They give you radioactive glucose. You wait for an hour to let your cells lap it up. And then they start looking because cancer cells have higher metabolic rates. And they lap that stuff up. Now, inflammation can do certain things. But the radiologists that read these know how to read this stuff. This is hot color. This is just lung tissue. This should all be blue. This is a not good place here. This is unhappy stuff here. So it's like multiple myeloma, which is it's in your spine and then it starts to go to your ribs and stuff like that. So isotopes are very important for a lot of reasons. PET scan, positron, emission, tomography, incredibly expensive. So your insurance companies will fight you to do anything else first. But if you have cancer and they suspect. that it is above stage one, they will scan your entire body to see if any lymph nodes are involved so that they know what's coming and they know what to do in surgery. Now, if it's melanoma on your skin, they do that a different, a little bit different way. They don't do a PET scan, they do something else usually. But so this stuff is incredibly important. There is a job that you can do. called nuclear medicine technologists where you go to school for a couple years after a bachelor's degree and you are injecting the isotopes and then doing the radioactive scans and things. Of course, you're in a room like not being exposed to the radiation. And the radioactivity is minor and it wears off after a certain amount of time. Molecular shape is critical to life. This is encalphan, which is similar to endorphins, which you've heard about. If you know while you're doing exercise, endorphins and encalphans circulate in your bloodstream. So if you've injured yourself slightly, you may not notice it until after that level goes down. Morphine, and I know, you know, I don't expect you to look at this picture and see the similarities, but right here, morphine is similar to your natural pain relievers, but morphine is much stronger. Now, it's obviously a substance that is manufactured. And so because of the molecular shape that's similar, it can be used in pain relief. And then taste is totally a chemical thing. I have a question. Why are there so many side effects of nausea when it comes to morphine? It's because it is hitting allied receptors at the same time. Some people don't get nauseous and some people do. Some people, your secondary receptors that it hits are more sensitive than others. For some people, morphine doesn't make you nauseous, but for some people, codeine makes you like really nauseous. I was like that. Codeine was like, oh, no. Okay. So taste is incredibly chemical. And there's sweet, sour, bitter, salty, and this umami, which is the savory kind of taste, which they've added. Okay. We're going to ask you to read a little about Vanderwall's forces. Lizards have these special cells in their feet and their toes that blink charges on and off. Vanderwalls occurs. We're going to talk about nonpolar molecules. There's two kinds. There's London dispersion forces and just Vanderwalls plane forces, dipole-dipole forces. London dispersion forces are intermolecular forces between nonpolar molecules, so we're going to center on those. Literally, they help lizards to go up walls. And what happens is in an atom, as the electrons move, this side, the electron is here. It blinks negative. It's not a full negative charge. It's not a partial negative. It blinks negative. Then the electron moves and this side blinks negative and that side blinks positive. And these forces kind of hold like the lizards onto the wall. We can't do that. We don't. have that ability. We're going to ask you to read a little bit about that one because it's a little bit complicated. Okay and then of course we talked about this a little bit in the beginning. This is my cabin in Iceland. My husband and I. This is the northern lights. This is oxygen ions that excited and are emitting green light. They're up in the atmosphere at 600 to 800 meters when this happens. You cannot believe. My favorite is nitrogen at 300 to 400 feet, and we get that sometimes there. This happens every time the sun does a coronal ejection and ions are coming over at the poles. It hits the ozone layer and starts to excite the ions, but you can't see it in the summer. Probably mid-September. If you ever want to go see this anywhere, Norway is a good place. Iceland is kind of cloudy. So even though it's there, you may not always see it. So if you ever want to go see this, you want to go in the winter. You said this is in Sweden? This is in Iceland. Oh, Iceland. In Sweden, they have them in Sweden too. All the Nordics, this extreme north, Finland, Sweden, Norway, Iceland, near the poles. Alaska. Alaska has incredible ones. I used to live in Alaska and see them there all the time. It has to be clear so you can see them and dark. And the problem with the Nordic countries in the summer is it's light almost 24 hours a day. So they're up there, but you can't see them. They're incredibly beautiful. It's just amazing to watch them. And they move. They move all over the sky. And sometimes you'll get the green and then you'll get the red fringe and then you'll get white. And I promised to give you a picture, which my bad, I didn't. do and I will do. I'm going to try. I got to get it out of my cell phone and try to post it in web courses. It's over. Here it is. I wish I could just airdrop this to you. It's a picture over Northumbria, UK. Earlier in the summer, there was this huge level five to six mass coronal ejection. And when it hit the atmosphere over the northern poles, it's purple, dark green, light green, yellow, orange. It looks like a rainbow and it's fluorescent in the sky. I've never seen them like that before. You know, it was pretty amazing. So this is all chemical phenomenon. That's why we're talking about it. So please come to office hours if you need help. Now I'm going to ask Andrea to say a few words about her SI sessions. She is a free tutor that has been trained to help you that has taken my class before. Take it away Andrea. Thank you Dr. Thomas. So hello everyone. My name is Andrea and as Dr. Thomas said, I offer free tutoring from SARC which is the Student Academic Resources. So I'll be hosting four sessions a week. On your Canvas or web courses you'll be able to see a module that says SARC SI Peer Tutoring for Biology 1. There you'll be able to see my schedule. My sessions begin tomorrow. I will have one at 10 a.m. at TA. TA is the Teaching Academy building which is like right across the pond. If you have any question on how to get there, you can, of course, reach out to me. SI sessions are a place where you can come, ask questions, work in group, review everything you've seen in lecture. I also provide you with a lot of resources like CAHOOTS, exam reviews, which will happen closer to when your exam day comes. I will be sending announcements every week to let you know. what resources I can give you and when the sessions are happening. Yes, my session on Wednesday is on Zoom. It's at 6.30 p.m. if I'm not sure. I will send an announcement later with all this information, letting you know how to get the Zoom link and how to register for sessions. If you're going in person. There's no need to pre-register. You can just go to the session and be there. You don't have to stay for the whole hour. You can and you can go at any time. And I'll also be attending the lecture. So if you have any question about this, you can reach out to me. And I have in the syllabus. So on your homepage of WebCourses, I have put in all of Andrea's SIDs and times right into your syllabus. And, you know, she will be, we'll let her put up her links and do all kinds of things. She should be able to do that right in web courses, hopefully. But if you can't, let me know, Andrea, and I'll put them up there. Or we'll do it in lecture. Okay. Any questions? Again, labs do start this week. So, you know, if you, you know, haven't gotten your lab sorted out, you want to make sure to do that. I will be posting this video. It may take me a little longer today. And I am going to stop.

on this computer. And good morning to everyone. Welcome to the Zoom.

So again, if you're new to the class, my name is Pam Thomas. This is Biology 2010. Okay, so first order of business, a couple announcements. And I've said this before, but I'll say it again.

There are still 520 students that have not gotten their lab together. You know, you need to purchase the universal, you need to get the icon, you need to download the icon. There's all kinds of directions in the lab web courses. Lab is not in web courses or Canvas.

It's not in Zoom. It's in universal. There are labs this week.

So this week at your lab, day and time that you're registered for, you will go into the lab. There's one exception to this, that's if you have lab one Thursday between 2 and 5 30. UCF has a football day on Thursday, so the university closes at 2 p.m. Michelle Yergin is the master lab professor over all the lab teaching assistants. She will post a message in your lab web courses that If you have lab one Thursday, usually she'll give you access throughout the whole week to do it at any time. But she will post that announcement.

It's probably already there. So you want to look for that if you're a Thursday lab that's affected by the football. Okay. So today we're actually going to start to do a little bit of biology. And we're actually going to do some chemistry.

These are jellyfish. They're kind of pretty ones. And they have certainly a lot of chemical defenses in their stingers. You know, everybody who's ever encountered a jellyfish and gotten stung knows that's not pleasant. You can neutralize it with sodium bicarbonate, actually.

But you have to be careful because that pH is wrong for your skin. And so you have to be careful how you do that. So... We're going to be talking about the chemistry of life. For all you chemistry majors, this is going to be super basic stuff.

We're not even going to go into a lot of things. We're going to get you just as far as we need to be to do cells. Some jellyfish are bioluminescent. This is due to the chemical called a quoran.

When it binds with calcium, it lights up and it gives off this blue glow. And if you are fortunate enough to have been in certain parts of the Gulf of Mexico at night at certain times, the bioluminescent marine life start to make the water glow. It's called blue flash. It's really, really interesting.

And in the Caribbean, in a lot of places, it's very intense. Around the Turks and Caicos Islands at night, some nights. You just see waves that are like fluorescent rolling in.

It's really pretty interesting. And Cocoa Beach, yes, you can see it there too. Okay, so over 76% of marine animals have some kind of bioluminescence.

It's not all based on a quorum. And we actually can use this bioluminescent chemical in lab experiments to help us light things up and show. if things are present.

Okay, so life depends on chemical reactions. Matter takes up space and occupies mass. This is kind of like in your high physical science.

There are actually more than 92 naturally occurring elements now, but we're going to say there's 92 that we're interested in. 25 of those are essential to life, and we're only going to talk about a few. that are really important in cells. And again, the PowerPoints are posted, so these major topics I'm hitting, you can already have those, and you just want to take little extra notes about what we're talking about. And I do have in the first module like sample notes for chapter two up so that you can see how to take notes if you're a first semester freshman and have never had to do it before.

So Four major elements that you see in 96% of living things. Hydrogen, oxygen, carbon, and nitrogen. And we can actually turn this around into a memory device. A very big one.

Memory devices. When I was in school, it was how I studied because I didn't want to spend a lot of time studying. So I turned everything in. Honk.

Hydrogen, oxygen, nitrogen, carbon. Okay. Four major elements that are in a lot of things we're going to talk about in life. Alright, let's stop this.

It's being fussy. I guess I'm going to have to erase it. Usually you could just clear, but they keep changing this all.

Okay, I'm just going to stop that. So there are other elements, certainly. Phosphate, calcium. Sulfur, potassium.

I mean, these are all also in cells. Potassium is really important in cells, but they're at much lower levels. Are both lectures at 9.30 and 10.30 the same? Yes. Okay, I see you, Andrea, at the end.

So trace elements. are required in small amounts, things like zinc, for enzymes to work a lot of times. What is an element?

An element can be broken down into any other substance by a chemical reaction. So it's like the atoms that are all together. Okay. Oops. So to show you what happens when living things are not too happy, you see this a lot in Florida.

These little, you know, this is like a giant zamiya. It's a very ancient plant. Inside the leaves look like stained glass windows. It's incredible in there what the structure looks like.

They're really pretty inside when you look at the leaf structure. This is a magnesium deficiency. Lots of people think when things turn yellow in the plant world it's an iron deficiency. This is a magnesium deficiency here. This is an iodine deficiency.

And so with the iodine deficiency, that can lead to enlargement of the thyroid, which laymen call goiters. That can become a life-threatening situation. We don't see this a lot in the United States because if you look at your salt, it says this salt is...

iodized. That means they've added just enough iodine to prevent this from happening to you. If you go to work for any of the, you know, World Health Organization, UNICEF, any of those, and you're working in other countries that don't have iodized salt, you will see this.

So you all know what atoms are, but we're going to go over this. We're starting from the beginning because In Florida, lots of students have not had lots of different things. Different schools, even though they're supposed to be unified curriculum, don't cover certain things.

So we want to make sure everybody has the basics. Atoms are made of protons. There are the positively charged particles in the nucleus.

Neutrons, they're the non-charged particles in the nucleus. And electrons, these are the things on the orbitals that go around. They are negatively charged, right? Atomic number is related to the number of protons.

Atomic mass or weight is the protons plus the neutrons in the nucleus. Now, there are orbitals and energy levels, and we are not going to get that far into this. We're not going to talk about...

p3 and hybrid orbitals or any of that kind of stuff. That's what you're going to talk about in your chem class eventually. So the outermost orbital of every atom is called the valence shell. This valence shell, this outermost shell, those electrons are the ones that participate in the chemical reaction.

Either they make sharing bonds or they transfer electrons back and forth. So the valence shell is very important in atoms because this is where the chemical reactivity occurs. Now, these words are really close. Valence denotes the bonding capacity of an atom. Valence by itself, not valence shell.

Valence, this is how many electrons an atom needs to gain stability. So by itself, the word valence means how many electrons an atom needs to gain stability. This is a reflection of how many bonds it needs to make.

to become stable and we're going to talk about what stability is. Okay valence electrons or valence shell electrons. This is the number of electrons in the outer valence shell that are existing. So valence shell electrons or valence electrons. How many are already there?

It's how many are sitting parked in the outermost orbital. That's valence electrons or valential electrons. Valence by itself, how many you need to get to stability. And stability is defined by certain numbers of electrons, which we're going to talk about. Some people are saying, why didn't we do chapter one?

Because chapter one is just everything. They try to tell you everything in biology in one chapter. which is totally useless. So your first exam will be on chapters 2, 3, and 4. We're not going to do chapter 1. So here you can see protons, the neutrons, and this is one valence shell with some electrons. This is hydrogen.

Hydrogen is a tiny little atom. Okay, let's put this here. What is a cation?

Cation is an atom that's ionized in a certain way. Cations lose electrons. They give them away. So they're in a negotiation trying to bond to satisfy stability, which we're going to talk about the octet rule. And they give away an electron, one or two or three or however many, in that process.

When they give away an electron, they have less negative now and more positives in protons in the nucleus. A neutral atom has the same number of protons as it has electrons, and the pluses and minuses balance out, so there's no net charge. In cation, when you lose electrons, you get a positive net charge of some kind, plus one, plus two, plus three. In anion is an atom that has gained electrons. So in the negotiation to try to get stability in the chemical reaction, they gain electrons.

They then have more negatively charged electrons in their outer shell than they have protons in there. nucleus and so they have a net negative charge questions yet you pause so do cations have a net positive charge because they give away that um yes and so you know basically i'm going to kind of so here's a little ad i'm Here's the nucleus. Let's say we had three protons here and we had three electrons out here. Let's say there was another one in here.

There are two electrons here. This is what we're looking at. And let's say we have three protons. Let's say we give away two electrons. Now we have three positives in here and we only have one negative.

This is going to have a plus two charge. Did that make sense? Yeah, because there's more protons than electrons. Other questions about anything?

So the cation is like lose electrons to obtain like... Stability. We're going to talk about what the octet rule means and... how you get stability and what does that mean.

Realize it is not something you have to install. Universal is what you need to install. Okay. Octet rule. Here we go.

Octet rule is a rule that governs the chemical reactivity of atoms. So what they're doing with their outer orbital valence shell electrons. Are they giving them away? Taking them? Are they sharing them?

Because they can do that. Are they sharing them equally? Are they sharing them unequally? You know, there's a lot to unpack here. So atoms react to get stable in their outermost shell, their valence shell.

So there are big atoms. There are really big atoms, but we're not going to go there. We're not going to have big atoms. We're going to talk about carbon, hydrogen, oxygen, nitrogen.

And these... have two rules. Okay, most of them will want to get eight electrons for stability. So however many they have, they're going to want to get eight. That may mean giving away electrons, taking electrons, or sharing electrons.

Hydrogen is the exception. Hydrogen is this tiny little atom. It only has, this is the nucleus here. protons, here's the neutrons. It has, it can take a maximum of two electrons and it only has one shell.

This is how it goes with atoms. If an atom is bigger, let's say we have two shells, the first orbital can only ever take two electrons. This is the nucleus.

That's because the nucleus is like a cloud and it kind of gets in the way. with this first orbital. So you can only ever put a maximum of two electrons in the first orbital, okay, when you're, if you're running this out, and we will. And then you can have up to eight electrons out here. Hydrogen only has this first orbital.

It doesn't have any more because it's a tiny atom. So it's the exception to the octet rule where two will give it stability. All the other atoms that we're going to talk about need to get to eight for stability, whether they give them, take them, the electrons, or they share them.

And we'll be talking about that. Okay, it's irritating to have to keep doing that. All right, used to be able to just clear it.

Okay, so all right. So here we're looking at oxygen. eight protons, eight neutrons, two electrons in the first orbital, six in the second orbital. It can take two more out here.

Okay, to satisfy the actant rule it would typically, it depends what it's what what the how do you know if it's going to give electrons, take electrons, or share electrons. It depends where it is in the periodic table of elements. We are not going to ask you to memorize the periodic table of elements, thankfully.

But some of these elements are very electronegative, and we're going to talk about that. So that showed oxygen. We're going to look at a little bit more about valence now. We want to know the valence of these.

So how many electrons does hydrogen need? Usually it has one and it needs one. We're going to use the memory device. Honk, hydrogen one, oxygen needs two, nitrogen needs three to get stability, and carbon needs four.

Honk one, two, three, four. Now you know the valence of hydrogen, oxygen, nitrogen, and carbon. And again, this is a reflection of the number of bonds they're going to make.

And bonding is different with different elements. Like when two oxygens are together in the air, when you're breathing in oxygen, it's O2. That is called a nonpolar covalent bond. And we're going to see this. Nonpolar covalent bonds, there's absolutely equal sharing.

So the two oxygen atoms back up next to each other. You get some electrons and then I get them and then you get them and then I get them and then you get them and then I get perfect sharing, equal sharing. Nobody hogs the electrons a greater percentage of the time. I'm going to have to, I used to be able to just clear this. They keep thinking they're making Zoom better, but they make it more cumbersome to use.

Okay. All right. So if in Adam. I have a question.

Yes, go ahead. About the valence. So there's six on the outside.

You said the valence is two because the ones in the middle shell have to go to the outside. And that's why the valence is two. Okay. So.

Let's draw this. So this is the nucleus. These here never do anything.

They can't go anywhere. They can't do anything because there's another shell outside of here. This is the valence shell out here.

Valence shell electrons. There's six out here. You have to add two more out here.

Nothing can happen here. They literally, so they would like come to another oxygen atom. If it's the air. And they would literally start sharing the electrons to get, you would get eight for a while and I would get eight for a while.

Does that help a little bit? Yeah, I suppose. Okay, we're gonna, we're gonna keep talking. On the slide before that, you said the number of electrons is a reflection of the bonds. Yes, so.

You know, basically, when you add two electrons, it means you have to bond in some way to another atom to be able to either share them or sometimes, ionically, you rip them off. And we're going to see examples of this. So if an atom has six total electrons, here's the nucleus, you would have two in the first shell.

and 4 in the second. That's 6 total. Not 6 valence shell, 6 total.

This is carbon. If an atom has a charge of negative 1, it's an anion, negatively charged ion. The first orbital from the nucleus only ever holds 2 electrons. If an atom has 7 total electrons, there's the nucleus, two in the first orbital and five in the second orbital. It needs three out here to get to stability.

This is nitrogen. Nitrogen needs three, has five. This is, I know if you've never seen this before, you're probably thinking, OMG, but it will get better.

You know, We're not going to do chemistry forever, which is really good. And the good news is your final is not comprehensive. So as you get through each test, you're making it through and getting along.

Okay, and so here are all the answers. Bonding. So let's talk about this sharing or this giving of electrons.

There's three major types of bonds. It's really important that you understand this. So if you read it and you study it and you're confused, this is why we're going to have Andrea, your SI leader, talk a little bit soon about SI sessions, help sessions. Also, Anika, your TA has office hours. I have office hours today at 2. I may be a little bit late.

I have meetings going on still. It's insane. It's the first couple weeks of class, but I'll be there eventually.

Your other TA, Kayla, has lots of office hours. The office hours are all posted in the syllabus. And Andrea is going to talk about hers in a little bit. So electrons are shared in covalent bonds.

Polar covalent bonds is unequal sharing. Non-polar covalent bonds are equal sharing. I'm going to say that.

The non-polar covalent is... equal sharing, like with hydrogens or oxygens. The two elements, the two atoms have the same pull, and so they're sharing absolutely equally. But there can be also these non-polar covalent, where one atom is a bigger electron hogger than the other atom in the pairing.

And so the bigger, stronger atom hogs the electrons. a higher percentage of the time. It's sharing.

They don't rip them off. They hold them longer. When the atom that is bigger and stronger... holds electrons longer and then finally gives them a little bit to the other element, it's called electronegative.

Electron-hogging elements are electronegative. They are typically found in row number seven in the periodic table. Fluorine, chlorine, bromine. Ah, they are so reactive that they will literally rip electrons off.

And they will go ionic most of the time. Water is an example of some substances like hydrogen and oxygen that form polar covalent bonds. And we're going to show you this.

So polar covalent bonds occur between molecules of a single atom. And we're going to indicate pluses and minuses. They're usually associated with partial charges forming, not full charges. It's not plus one, minus one. You see this squiggle sign.

This is, then you'll see like four or three, or you'll see plus or minus. Most of the time you're going to see plus or minus. Partial charges happen because of this electron hogging electronegativity. Electronegativity is the tendency of an atom to pull and hold electrons, but not forever. It doesn't rip them off.

It doesn't hold them and never give them back. It gives them back eventually for a partial time. So we're going to show you.

Here is a water molecule, okay? There's oxygen. These are the hydrogens.

Oxygen is big and it is an electron hogger, but it's not so much of a hog that's going to take the electrons and keep them. So in this sharing, if we look at this for 100 seconds, for 90 seconds, the oxygen would keep these electrons orbiting. It becomes partial, this is a partial sign, partially negative. The hydrogens, which are little and puny, it's like when you, if you're like ever pulled a rope, you know, in a game, and like there's too many people on one side, and they just pull and you go flying, the hydrogens don't have enough pull.

So they do get the electrons once in a while. like maybe this one gets it for five seconds and this one gets so they become partially positive again this is not plus one minus one these are like partial charges okay and so here you can see it and these partial charges are attractive and hold the hydrogens to the oxygen okay questions about this Isn't water special because it can offer its valence electrons to form dative bonds, and that's also what makes it a good ligate? Yes, but first semester freshmen don't know that yet because they haven't had chemistry.

You must be a chem major. Yes. No, I'm a biomed. I'm also a freshman. Okay.

Oh, wow. So did you have like IB or something? No, I just did a little bit of learning outside of.

Okay, that's cool. Yes, that's all correct. And everybody else, don't worry about what he just said. Okay, now we're going to switch to another kind of bonds, ionic bonds.

This is where the electron hog is such an electron hogger. It's like so extreme that it backs up to the other atom and literally pulls the electrons out of the atom's orbital and steals them, literally. OK, this is ionic. This is where you get full charges like plus 1, minus 1. Literally, electrons are being moved permanently into other atomic orbitals, outer orbitals. This occurs, and you get the cations and the anions.

OK, so we're going to do something here first because I want you to see this. We're going to look at table salt. Okay, so chlorine has 17 electrons. Now, I know I promised you we weren't going to do big ones, but this is a big one.

This has three orbitals. There's the nucleus. We have two in the first one, eight maximum in the second one, and we have seven left over.

Chlorine is incredibly reactive. It gets near other atoms and says, I just need one more. So I'm going to force you to react and I'm going to rip off the electron.

And it does rip off the electron and then it takes eight and then it becomes negative one. This is why we get so excited if you get an accident with a train car full of chlorine gas, because it will react with your lung tissue, with everything. It's taken that electron.

Like nobody has anything to say about it. Okay. It's extremely electronegative. This and fluorine are some of the most electronegative things in the world.

And so they're very toxic to humans in certain forms. Now we use chlorine in our pool and diluted in order to kill germs and kill algae and stuff, which it fries really quickly. Okay, what is something with chlorine in it?

Chloride, sodium chloride, table salt. This is an ionic bonded substance. Na sodium and Cl chlorine, NaCl.

What you eat on your food. Let's look at how this works. Now we're going to see an ionic bond happen. think they messed up here.

Let's see. We should have 1, 2, 3, 4, 5, 6, 7, 8. And here we have 1, 2, 3, 4, 5, 6, 7, 8. And here we have, there should be, yeah, this is your book sometimes. There should be another one right there. There we go. So here's sodium.

Here's its valence shell electrons. There is not enough energy in the world for this to add seven to get to eight. So it wants to get rid of this one.

It says, if I can just get rid of this one, I drop back to the second orbital where I already have eight and life is good and I have reached stability. Chlorine has seven and needs one. So sodium gets near chlorine. Chlorine says, give me. you're one now i have eight on my outermost valence shell i am happy okay and this is the valence of chlorine how many does it need it needs one to get stability it takes that one from sodium now chlorine's outer orbital is at eight it's happy sodium drops back to this orbital which is now the outermost orbital that's filled it has eight everybody's happy and we have table salt, which is what you use every day. This is an example of ionic bonding, and, okay, I have to do this again, the sodium becomes plus one, because there's now, this had like two, eight, and one it had 11 so this has 11 protons in the nucleus and this um basically what we do is we now have more protons and minus one electron is going to happen so this becomes a cation and this gets a negative one so this becomes an anion sodium is plus one chloride is negative one everybody's like omg oh clear all drawings that's what i want okay so questions about this so this is ionic bonding they literally rip them off from each other give them take them and they never go back where they were again they stay with those atoms okay And then there's Hydrogen bonding.

Hydrogen bonding is so confusing for students a lot of times. Hydrogen bonds are between multiple water molecules, as an example. This is one example, and we're going to show you this.

So, whereas polar covalent bonds were between... the atoms of a single molecule of water. Polar covalent bonds were between the atoms of a single molecule of water.

Hydrogen bonds are like this attractive bonding glue that stick together multiple water molecules. So you're going to find hydrogen bonds between different water molecules. and we're going to show you.

Okay, so I'm right again. Let me use a different color. What color do I want? So right here, this is a hydrogen.

This is an oxygen. This is a hydrogen. It's like Mickey Mouse. These bonds are polar covalent right here.

It's a P. This is a single water molecule. Polar covalent bonds, I'm saying it again, are between the atoms of a single molecule. In this example, a single water molecule. Okay, this becomes partially negative, which is hard to see here.

These become partially positive. Now, what hydrogen bonds are is between the molecules. Here's a hydrogen bond. This. This.

Here's a hydrogen bond. Here's a hydrogen bond. These are the hydrogen bonds between multiple water molecules holding the water together.

What is the force holding them together? The partial negative here and the partial positive hydrogen here are attracted to each other like little magnets. And so partial positive here, partial negative here.

You can see it in black here. So hydrogen bonds. Oh boy, my clock's going off.

Sorry. Can you guys hear that? Okay, now it's done.

So hydrogen bonds are between multiple water molecules holding them together, whereas polar covalent bonds are in each. Single water molecule, I'll do this in green now. In green, we have where the polar covalent is. In each individual water molecule, that's polar covalent. Between all the water molecules, hydrogen bonds.

Questions about what we're saying here. This takes some time to look at. So if you've never had chemistry before, Don't panic.

It takes a little while to get used to all of this. So the hydrogen bond holds together the like multiple molecules of water together. Yes.

So it has it has a partial negative and a partial positive in the bond. OK, so what is happening is the oxygen. is partial negative the hydrogen is partial positive and so literally this is what's sticking the bond together like glue it's kind of like if you put opposite ends of the magnet together and you can feel the force that's what this is it is literally holding a glass of water all those the liquid water molecules are being held together by these hydrogen bonds that they don't come unglued does that help a little bit Thank you.

Yes. Okay, good. All right. Other questions?

Professor, someone asked, is polar equal or non-equal? Polar covalent is unequal. So let's look at this. So here, if we look at this, this one is the electronegative element.

This is oxygen. It's a hogger. It's an electron hogger. So if we looked at this for 100 seconds of time, where is the electron at?

Okay, to say it in vernacular, where does the electron reside most of the time? 90 seconds here. Whoever has the electron longer becomes partially negative.

Here, we do share, but it's grossly unequal sharing. So we only get the electron for five seconds. We become partially positive.

And this hydrogen, these are all hydrogens, only has it for five seconds, so it becomes partially positive also. That's why these are partially positive. So polar covalent is really unequal sharing. Yes, that it is sharing, but one of the electron hogging elements holds those electrons in their orbital for a really high amount of time and then gives them back for a little bit of time to the poor puny hydrogens.

They're small atoms. They don't have pull. They can't fight back. Does that help?

Let's just do this. Okay, so what is this? These bonds here, a single molecule of water. This is a polar covalent bond. This is another polar covalent bond.

Between the water molecules, this is a hydrogen bond. And then I gave you the answer so that you can try this stuff. And here's just a picture. It's kind of blurry.

All these polar covalent dot bonds. And then there's polar covalent and solid. And there's hydrogen bond in dotted lines.

Okay. We're doing pretty well right now, which is good. So we're going to talk for a minute about isotopes.

Isotopes. have different numbers of neutrons in the nucleus. So what you'll and a lot of they're not all radioactive. Many of them are radioactive but they're not all radioactive.

A lot of times the radioactive isotopes, so you'll see carbon 12, carbon 14, different number of neutrons in the nucleus. Same element, different number of neutrons. That's what isotopes are. There are a lot of medical uses for the radioactive ones.

I had to have, so I've had cancer like a couple of times. Two years ago was the last time. Different cancer both times. I'm good now. Thankfully, hopefully I'll stay good.

But this is a PET scan. PET scans, I had to have one of those in February. They give you radioactive glucose.

They check your glucose level first to make sure it's low, it's normal. They give you radioactive glucose. You wait for an hour to let your cells lap it up. And then they start looking because cancer cells have higher metabolic rates.

And they lap that stuff up. Now, inflammation can do certain things. But the radiologists that read these know how to read this stuff. This is hot color.

This is just lung tissue. This should all be blue. This is a not good place here. This is unhappy stuff here.

So it's like multiple myeloma, which is it's in your spine and then it starts to go to your ribs and stuff like that. So isotopes are very important for a lot of reasons. PET scan, positron, emission, tomography, incredibly expensive. So your insurance companies will fight you to do anything else first.

But if you have cancer and they suspect. that it is above stage one, they will scan your entire body to see if any lymph nodes are involved so that they know what's coming and they know what to do in surgery. Now, if it's melanoma on your skin, they do that a different, a little bit different way. They don't do a PET scan, they do something else usually.

But so this stuff is incredibly important. There is a job that you can do. called nuclear medicine technologists where you go to school for a couple years after a bachelor's degree and you are injecting the isotopes and then doing the radioactive scans and things. Of course, you're in a room like not being exposed to the radiation. And the radioactivity is minor and it wears off after a certain amount of time.

Molecular shape is critical to life. This is encalphan, which is similar to endorphins, which you've heard about. If you know while you're doing exercise, endorphins and encalphans circulate in your bloodstream.

So if you've injured yourself slightly, you may not notice it until after that level goes down. Morphine, and I know, you know, I don't expect you to look at this picture and see the similarities, but right here, morphine is similar to your natural pain relievers, but morphine is much stronger. Now, it's obviously a substance that is manufactured.

And so because of the molecular shape that's similar, it can be used in pain relief. And then taste is totally a chemical thing. I have a question. Why are there so many side effects of nausea when it comes to morphine? It's because it is hitting allied receptors at the same time.

Some people don't get nauseous and some people do. Some people, your secondary receptors that it hits are more sensitive than others. For some people, morphine doesn't make you nauseous, but for some people, codeine makes you like really nauseous. I was like that.

Codeine was like, oh, no. Okay. So taste is incredibly chemical.

And there's sweet, sour, bitter, salty, and this umami, which is the savory kind of taste, which they've added. Okay. We're going to ask you to read a little about Vanderwall's forces. Lizards have these special cells in their feet and their toes that blink charges on and off. Vanderwalls occurs.

We're going to talk about nonpolar molecules. There's two kinds. There's London dispersion forces and just Vanderwalls plane forces, dipole-dipole forces.

London dispersion forces are intermolecular forces between nonpolar molecules, so we're going to center on those. Literally, they help lizards to go up walls. And what happens is in an atom, as the electrons move, this side, the electron is here. It blinks negative. It's not a full negative charge.

It's not a partial negative. It blinks negative. Then the electron moves and this side blinks negative and that side blinks positive.

And these forces kind of hold like the lizards onto the wall. We can't do that. We don't.

have that ability. We're going to ask you to read a little bit about that one because it's a little bit complicated. Okay and then of course we talked about this a little bit in the beginning. This is my cabin in Iceland. My husband and I.

This is the northern lights. This is oxygen ions that excited and are emitting green light. They're up in the atmosphere at 600 to 800 meters when this happens. You cannot believe. My favorite is nitrogen at 300 to 400 feet, and we get that sometimes there.

This happens every time the sun does a coronal ejection and ions are coming over at the poles. It hits the ozone layer and starts to excite the ions, but you can't see it in the summer. Probably mid-September. If you ever want to go see this anywhere, Norway is a good place. Iceland is kind of cloudy.

So even though it's there, you may not always see it. So if you ever want to go see this, you want to go in the winter. You said this is in Sweden? This is in Iceland. Oh, Iceland.

In Sweden, they have them in Sweden too. All the Nordics, this extreme north, Finland, Sweden, Norway, Iceland, near the poles. Alaska. Alaska has incredible ones.

I used to live in Alaska and see them there all the time. It has to be clear so you can see them and dark. And the problem with the Nordic countries in the summer is it's light almost 24 hours a day. So they're up there, but you can't see them.

They're incredibly beautiful. It's just amazing to watch them. And they move. They move all over the sky. And sometimes you'll get the green and then you'll get the red fringe and then you'll get white.

And I promised to give you a picture, which my bad, I didn't. do and I will do. I'm going to try.

I got to get it out of my cell phone and try to post it in web courses. It's over. Here it is.

I wish I could just airdrop this to you. It's a picture over Northumbria, UK. Earlier in the summer, there was this huge level five to six mass coronal ejection. And when it hit the atmosphere over the northern poles, it's purple, dark green, light green, yellow, orange.

It looks like a rainbow and it's fluorescent in the sky. I've never seen them like that before. You know, it was pretty amazing. So this is all chemical phenomenon. That's why we're talking about it.

So please come to office hours if you need help. Now I'm going to ask Andrea to say a few words about her SI sessions. She is a free tutor that has been trained to help you that has taken my class before.

Take it away Andrea. Thank you Dr. Thomas. So hello everyone.

My name is Andrea and as Dr. Thomas said, I offer free tutoring from SARC which is the Student Academic Resources. So I'll be hosting four sessions a week. On your Canvas or web courses you'll be able to see a module that says SARC SI Peer Tutoring for Biology 1. There you'll be able to see my schedule.

My sessions begin tomorrow. I will have one at 10 a.m. at TA. TA is the Teaching Academy building which is like right across the pond.

If you have any question on how to get there, you can, of course, reach out to me. SI sessions are a place where you can come, ask questions, work in group, review everything you've seen in lecture. I also provide you with a lot of resources like CAHOOTS, exam reviews, which will happen closer to when your exam day comes. I will be sending announcements every week to let you know. what resources I can give you and when the sessions are happening.

Yes, my session on Wednesday is on Zoom. It's at 6.30 p.m. if I'm not sure. I will send an announcement later with all this information, letting you know how to get the Zoom link and how to register for sessions.

If you're going in person. There's no need to pre-register. You can just go to the session and be there. You don't have to stay for the whole hour. You can and you can go at any time.

And I'll also be attending the lecture. So if you have any question about this, you can reach out to me. And I have in the syllabus.

So on your homepage of WebCourses, I have put in all of Andrea's SIDs and times right into your syllabus. And, you know, she will be, we'll let her put up her links and do all kinds of things. She should be able to do that right in web courses, hopefully.

But if you can't, let me know, Andrea, and I'll put them up there. Or we'll do it in lecture. Okay. Any questions?

Again, labs do start this week. So, you know, if you, you know, haven't gotten your lab sorted out, you want to make sure to do that. I will be posting this video. It may take me a little longer today. And I am going to stop.

Transcript for:Biology 2010 Course Overview and Chemistry Basics

Transcript for:
Biology 2010 Course Overview and Chemistry Basics