what's up EP biop penguin so today we are going to go live and we're already live um and we're going to talk about uh unit three which is on sellor energetics um so I'm Mrs Jones from AP biop Penguins um and so real quick why are we Penguins well because of the fact that as AP Bio students you are dressed for success and so AP Bio penguins are of course dressed for success and they're cute little tuxedos all the good jzz um and as we go through this review session you're welcome to go ahead and put your comments or your questions down into the chat it's just me on here um but I'm happy to answer them as we go through each of the the pieces of information um and so real quick reminder you already probably know about the resources but just in case you don't um there's currently Daily Review happening Monday through Friday on my Instagram page so AP biop Penguins um if you go to my website my Weebly a 374 page review guide um in which I go through each of the topics in the CED asking you little topic questions I give you I statements and then at the end of each unit there is a multiple choice and free response questions to kind of help you to review as well as there are explanations for all the multiple choice and then there are scoring guidelines for all the free responses um I do an FR frq Friday um every week so I've been currently posting four every weekend um and so the goal is to get through all the F frqs by the end of the review season um and then there's 120 uh quizzes games on Weebly so again on my website um you'll get the access codes um and so you'll go to we I'm sorry you'll go to quizzes.com You'll type in that code and then you've got a game that you can use to review as well as there's review Powerpoints and all that is found on AP biop penguin. we.com or you probably just Google AP biop penguins and you'll probably see it as like the first hit um so today's plan we're going to work through enzymes we're going to talk about Cellar aspiration photosynthesis um I've got some practice questions for you two multiple choice and two free responses um well half of one of the free responses um and then I'll open it up in case there's any kind of question questions but of course if you have questions as I'm going through this go ahead and put them in the chat last week or I guess it was last weekend um individuals were kind of helping each other if I didn't see the question there is a little bit of a lag between when I say it and then of course you hear it and then whenever you have that moment to type it into the chat um so I may have moved on to the next slide but I'm happy to go back and answer any questions as you have them um so let's go ahead and get started so before we get into enzymes let's talk about free energy because this whole unit is about energetics and about the energy so first thing gies free energy so what is gies free energy well that's just the energy that's available to do work um so whenever we talk about reactions in your your cell we're going to talk about them either releasing energy or them absorbing energy um which will be called enonic and exonic reactions in a little bit and yes those terms were backwards um so there's equation this equation is not on the formula sheet it used to be on the formula sheet but I don't believe you're going to have to calculate this but but just in case I did want to show you the formula so this Delta G because it was asked earlier this uh week that Delta G stands for change um so it's just looking at your final minus your initial and how much the change in your free energy was um equals the Delta H so the change in the enthalpy um or the change in the the heat energy um minus your temperature which is in kelvin times your Delta s which is your change in entropy so the disorder um sort of the disorganization the chaos if you may and so with this we've got another formula that Delta g equals your final Gibbs minus your initial Gibbs which is where we're going to look at for our exonic and or endergonic reactions so with an endergonic reaction this means that energy has to enter the system so it has to be um brought in okay um and so this kind of reaction we're going to start with low free energy and then we're going to gain energy that Delta H right I mean sorry Delta G right here is going to be the we're going to have positive change in free energy and so our products are going to have more energy than our reactants did so this is going to be not spontaneous because it's not going to happen on its own it's going to require that input of energy in order for this reaction to take place it's going to absorb energy an example of this would be ADP plus inorganic phosphate giving us ATP this is a endergonic reaction you've got to have energy put in in order to be able to do this and that's what the process Sol respiration is doing is it's releasing the stored energy of a glucose molecule or another molecule and that energy that gets released will be stored in the form of ATP so exonic reaction has to do with that the energy is going to exit the system so here we see that our reactants have more free energy than our products so our Delta G is going to be negative because it's released that free energy I always tell students that EX for exit or the en en for enter okay so exonic reaction is releasing that energy so this will happen spontaneously yes there's going to be an energy of energy of Activation so that activation energy is required to get a reaction started but the overall process is of course going to release you can put a thick of dynamite on your table and sooner or later that thing's going to explode um that's why you always want to be careful with dynamite that you don't have any kind of movements which you're not working with dynamite so it's okay um and then the example would be ATP releasing that energy um in the form of ADP and that energy is not stored in that inorganic phosphate it just has to do with the structure itself has uh less free energy as ADP than it does as ATP so enzymes what are enzymes going to do well these are just your biological catalysts and if you've had chemistry you know that catalyst's job is just to speed up a chemical reaction so these are biological catus they're just things that are in your body that are going to speed up the reactions within your cells um and their job is to reduce that activation energy so we saw before that you have this energy of activation it's the amount of energy that's required to get the reaction started okay and so if you notice here the purple line is higher than the green line that is your uncatalyzed reaction so if there's no enzyme in there or there's no Catalyst that's how much energy is required to get the reaction started versus if you have an enzyme you have that Catalyst it's just decreasing how much energy is required it does this by binding to the different molecules and it can put them in the appropriate confirmation so they can then of course react it could kind of strain the bonds so that of course it helps to break that Bond um and so they do a lot of things to help to decrease the amount of energy required to start your Delta G is going to be the same so it's going to release the exact same amount of free energy or it's going to absorb like it's going to have the same energy Delta G will be the same it cannot make a exonic reaction endergonic nor an endergonic reaction exonic like it's not going to happen like that okay so important things to note is that these catalysts they're proteins so everything you learned about in unit one in terms of proteins applies to them okay they're still looking at the the the confirmational structure in terms of the primary secondary tertiary and cordary structures it's exact same thing we looked at before so when we talk about denaturation we're talking about proteins and how proteins break apart um they're not consumed by the reaction so you can use an enzyme over and over and over and over and it will never get used up it will never go away the only way to get rid of that enzyme is of course to to Nature it okay um and as I said before it has no effect on that Gibs free energy the free energy is the exact same um whether uh you have double triple quadruple the amount of of enzyme in there is still going to have the exact same Delta G the reaction would just occur faster because you have more molecules to react it but you're not going to be able to of course change that Delta gen so how do an enzy how how does an enzyme work so we're going to have this little active site that's the site of which our subrate is going to bind and once it binds as you know with proteins anytime you Bond into a protein it always changes shape and so if we were to have this molecule here right it binds into my hand I'm not just going to let this kind of pen roll around right naturally when someone puts a pen in your hand you close your hand hand right that's what's happening here is that substrate binds to the active site it causes confirmational shape change and when that happens of course now it's putting all these molecules in the appropriate orientation so now they're going to be able to react so as I said before decreasing that activation energy okay they react it releases that product back out and now the enzyme is ready to take the next substrate again again go through the reaction breaking apart to the top from the bottom and it goes on its merry way um as I said it releases it and so it's do this over and over and over again repeatedly okay so how can I stop it from happening well there are different things called Inhibitors so one thing is a competitive inhibitor a competitive inhibitor is going to compete for the same active site it has the same general structure so here's our substrate here's our competitive inhibitor it's going to bond to the same places it's going to have a same general sh shape just like um morphine and endorphins endorphins are natural in your body um but morphine which is a drug that was made by pharmaceutical company has a similar structure to the Endorphin which allows it to bind to the same receptors which gives you that same sense of euphoria um and helps take away that pain that you might be feeling um don't you yeah um and then we also have competitive non-competitive Inhibitors KN inhibitor are going to bind to another sh side okay so it's going to be an alisic site and when it binds that alisic site what's happening is the enzyme changes shape right the protein changes shape when you find something to it so now the activ site is no longer the same shape to allow The Binding of that substrate to it okay um and so when we look at this we're looking at these competitive and non-competitive Inhibitors they're going to bind and release bind and release constantly um and so if we wanted to overcome an inhibitor just increase the amount of substrate we also find that sometimes your product can inhibit um it's called Product inhibition and because the product was originally Bound in that spot it can bind again which can inhibit so if we're trying to increase our reaction rate you can of course increase temperature slightly you can increase the amount of substrate or you can decrease the amount of product all that can help you to overcome that inhibitor and so denitration so if we increase our temperature too too much like it gets really really high that causes these Bonds in our tertiary and our secondary and our quinary structure to break they are calent they're ionic bonds um and those bonds can break because of course you have more vibrating there's more kinetic energy as we increase that temperature um also pH you know that the carboxy group is acidic and the am group is basic and so because of the fact that you know that those groups are acidic and basic they will of course donate and pick up uh hydrogens or protons from the reaction I'm sorry from the solution and so that can cause a confirmational shape change the shape will change if you change the ph and so there's like a certain range the opal range so um you might be asked questions where you're looking at a graph and wondering why is it coming off on both ends well because of the fact that it's getting out of its um optimal range and so it's denaturing um why would I see this reaction slowing down because of den nature and so they'll often times they'll just give you some type of reaction that will make you see like oh this enzyme got denatured which caused the reaction rate to either stop or slow down okay um you could also see that we have a change in salinity the solinity can change the um ionic structures not ion structure but it causes ions to be in there which then changes the ionic bonding so then again the enzyme can Den nature so Cellar respiration so before we get into this I know that students have a hard time with cellation and photosynthesis and it's because of the fact that you overwhelm it like you get put too much stress in knowing all 10 steps um of glycolysis and knowing all eight steps of KB cycle and knowing every enzyme I didn't have to know any of that until I got to college in my biochem course and I sat in the library for two weeks and I memorized it all and do you think I still know it no I do not because I haven't had to use it so what I want you to remember is what goes in what comes out where where does it take place and why is it important okay and that's what we're going to focus on okay so there are three steps to cellular respiration you've got glycolysis crab cycle and then oxidative phosphorilation okay so glycolysis takes place in the cytool that means it will take place in a proc carot as well as a UK carot because it's just in that sosol it does not require a mitochondria for this process to take place and so this diagram is slightly wrong this should be ADP and this should be ATP um but other than that the diagram is correct um so we start out with glucose and then in this process we're going to make um two nadh's we make two py rates and then two atps again the diagram is wrong I should say ATP not ADP okay um so we start with glucose and thinking about the name glyco glyco means sugar Lis we know means to break so glycolysis means the sugar splitting step the step in which we're going to break glucose so we take glucose which is a six carbon structure and we break it into two three carbon structures okay so at this point I haven't lost any carbon dioxide oid so that's why I see I have the two two two two nadh's two pyruvates and two adps okay so that pyate is going to go through pyruvate oxidation and we're going to of course oxidize it okay so when we go through the oxidation process we then are going to make this thing called a caloa acetyl COA acetal group is two so in the process of pyu oxidation we lost one carbon dioxide we made one nadh um and you're wondering why I'm doing this I tell my students that that h means to hold so if I have any H is holding an electron if I have n+ it's not holding the electron and so it's a lie that I've told my students but it works out for me um and so the acetyl group comes in it loses the co-enzyme a the whole point of that co-enzyme a was just as a placeholder so the acetyl comes in it then binds to the molecule that's already in there the uh making the oxil acetate I'm sorry it binds oxil acetate making citrate not important don't worry about it and in this process we go through this Loop and this is going to take place in the mitochondrial Matrix so we had to actually be in The Matrix for this to take place so when we talk about CP cycle you have to have a mitochondria for this CP cycle okay so the star material C COA and in one Loop of the crab cycle or one turn we're going to have two carbon oxides remember aetl COA has two carbons and I make two carbon oxides which means at this point I've completely broken down the glucose there is no more glucose left it's gone okay um I have three nadh again they're holding those high energy electrons one fadh2 is the same as d h is just a little bit weaker it's still holding electrons and then it makes one ATP technically it's a GTP but that's okay you can just know it as ATP now glycolysis made two pyruvates but when I just gave you the explanation there was only one aceto COA so you'll actually have to go through the cycle two times if you're talking about breaking down one glucose molecule okay so the next thing I have is oxidative phosphorilation so as I said CB cycle gone we already used up all of the um glucose it's all gone right so all that's left are the high energy electrons so where is the oxid phosphorilation taking place well let me side for a half second and it's going to start out with these electrons the nadh the fadh2 that has all those electrons is going to bring it over here now there's two steps the first step is electron transport chain that's what you see right here this is our electron transport chain it's found in the mitochondrial christe so if you remember we had the mitochondria had the outer membrane and the inner membrane was like highly folded increasing that surface area allowing for more of this to take place in there um and so in that chiste we're going to drop off the nadh and that electron is going to go through this chain it's going to slowly drop in energy and as it slowly drops in energy each time it releases energy that energy is used to pump a proton as you see right here we have low protons here High protons there we're pumping the protons into the intermembrane space okay so that's all that's happening with our electron trans chain protons are pumped into the IM space if you're wondering where the i space is it's the space between the cryst or the inner membrane and the uh outer membrane so it's that inner membrane spaces between there and last time we talked about pH and we mentioned that when the pH decreases it means it's because there's an increase of H+ so the intermembrane space is actually really acidic okay um and so it generates this proton gradient so there's a high concentration of protons on one side and if you remember from unit two when there's a high amount of protons what it wants to naturally do is flow down its concentration gradient and so at the end of this whole thing we of course have our oxygen okay so why would I talk about the proton gradient because of chemiosmosis that's the second step of oxid phosphorilation so these high protons right the protons that we have our gradient it's going to flow down ATP synthes it ends in a so we know that's an enzyme this enzyme's job is to synthesize ATP so it's going to use the energy the potential energy that's uh stored in that high uh concentration and as the uh protons move across the membrane it's going to turn the turbine of ATP synth which is going to provide the energy needed to phosphorate the ADP now someone asked earlier this week on the review um where does the phosphate come from it's just inorganic phosphate it's just floating around inside the cell okay um and so as I said there are two parts of oxid phosphorilation the electron transfer chain okay the whole point of electron transfer chain is to make the proton gradient there's no ATP made here chemiosmosis is the second step and this is where ATP is made so hope that we've gotten cell respiration I don't see any questions happening in the chat remember if you have a question as I'm going through this go ahead and put in the chat it's just me but I can answer them as I go so three steps you have glycolysis we have crap cycle we have oxid phosphorilation so making sure we know where does it take place cytool Matrix christe um what does it start with it starts with glucose the cetto COA and then the electrons of nadh and fadh2 um we're uh why is it important it's important because it's making this nadh this high energy electron it's making the materials needed to go into the next step um is creating a proton gradient um so I hope that were helpful I don't really see any questions coming in so I think I'm going to write a rle one so I think it was 2015 or 2016 I can't remember the year exactly this question was on the exam in which they gave you the picture so those of you that are kind of freaking out like oh my God how do I remember all these steps they gave them a diagram and they just asked them to explain what they saw okay so use the information describe one contribution of each in the following of 18 PP synthase um so here we see we have our glucose again makes huate and I can see that there's two atps made so how are those ATP made well they're made by substrate level phosphorilation okay so that's one way that we can make ATP another thing look I've got nadh so I'm forming nadh that we know later on will go to um the electron transfer chain to provide that gradient right and the last thing I see is I've got this acet COA that ends here but starts there so it's going to produce the acetyl COA that's needed for the CB cycle okay so all you had to do was look at the picture a lot of these free responses if you look at the diagram and really kind of interpret what you see you can get a lot of points okay so the Second Step we're seeing here is how can I oxidize my intermediat of CP cycle and get it well of course I'm making ATP in the form of GTP again substrate level phosphorilation I can see that there's the nadh and the fadh2 that's also made that's going to go and become the gradient and then it's U producing those high energy electrons so again the diagram has the picture information for you and the last thing is how does the proton gradient help us in the electron transfer CH that gradient is then going to provide the energy that's needed to move through ATP synthes to synthesize ATP that was not nearly as easy because you're going to have to know a little bit about the process but you could of course apply that okay so that gets us to the end of Cellar respiration are you ready for photosynthesis okay so photosynthesis is going to be made up of two steps we have our light reactions and we have our Calvin cycle the light reactions are going to take place in the thilo covid okay the same thing we saw with Sol respiration we need to know um what does it start with what does it end with where does it take place and why is it important okay so it takes place in thid membrane so if you remember the chloroplast right we had the outer membrane we had the inner membrane and then there these little stacks those Stacks were called Grana and the stacks were made of these little stacks um and that was thyo covid okay so it's in the membrane of that and the reason why plants are of course green is because the fact that there are there's chlorophyll within the membrane that's what this p680 and the p700 is that's molecule of chlorophyll and actually there's chlorophyll making up this whole reaction complex here um and those pigments are going to absorb that light energy and so the reason why it's green is because it's reflecting green back okay um and so your eyes see the green that's reflected so of course if you saw there was an action Spectrum I think on the 20 14 exam um in which they were looking at which one of these is the appropriate molecule for uh photosynthesis and you would of course realize that the one that reflects in the green wavelength you know that was your um the the chlorophyll they were comparing bacterioopsin and chlorophyll sorry Sidetrack sorry um so what does it start with it starts out with water so right here you see the water molecule is going in it's getting broken down it's releasing that oxygen so how interesting that in respiration we use oxygen as our final electron acceptor and it made water but now water goes in and it acts as the way that we break the water and we get oxygen and our electrons back so hm maybe a way to remember it um we also have photons coming in the form of light energy and so in our first reaction complex this is actually photosystem 2 okay we're going to absorb that light energy um it then moves down this electron transport chain here and oh my gosh we have an electron transport chain what does that mean again we're going to see our protons moving against their gradient right there as the energy Falls protons pump so it's going to pump over here into the thilo covid space so uh in respiration it was out into the intermembrane space now it's in to the thilo covid um and so we can see that this is going to generate that gradient and then at the end we see ATP synthes that's going to of course synthesize the ATP okay so this electron went through the electron transfer chain then went into photosystem one gained more energy and then it's going to go to NAD pH the P stands for photosynthesis yeah I know it's a lie but that's okay and the H stands for holding so when I have nadph that means that I am holding the electron in photosynthesis um and so the products ATP and adph ATP is made because of this proton gradient here and the nadph is made over here um there's a book it's called as the sun shines um and it kind of gives a see if I can share that later so y'all can see this if you needed to um but I've got that for you and so as I said protons are pumped against Sil the covid space um so we can create that proton gradient okay so there's two ways the electron can flow in photosynthesis we have linear electron flow that means I got photos system 2 electron transport chain photos system one nadph this is going to synthesize ATP and adph in a one: one kind of way like you make equal amounts of each of them okay versus cyclic flow is going to go from photosystem one and it doubles back and it goes only through this electron transport chain so the function of this is going to allow us to make ATP without making nadph you'll find out in a second why but is allowing us to make nadph without making the ATP okay um so this is going to be important um because in the Calvin cycle we're going to need um nine molecules of ATP and only six molecules of nadph so there there's not that one to one that we're going to see okay so Calvin cycle taking place in the stroma in case you don't remember the stroma is the um kind of the cytool of our chloroplast um and so we're going to use uh three carbon dioxides um nine atps and six NAD PHS okay the CO2 is going to come in um it's going to bind to something called rubp with the enzyme rabisco um it then goes through a whole big breakdown in which it's going to make something called g3p if we had gone through all the steps of glycolysis you would have seen that at step five there's a molecule called g3p glycer alide three B sorry three phosphate and so that's what we're making here that g3p could then take two g3ps put them together and you then make glucose again okay um then we have to regenerate the NAD I'm sorry the rubp from that okay so the product is g3p and so there was somewhere I was going to make sure I mentioned in this I can't remember what I was going to say okay somebody is asking will you do Fitness um so so if you're thinking about Fitness there is a C4 and C3 um in Camp plant in terms of photosynthesis um so the C3 is what we normally see um so right here it's going to break and make a three carbon structure um and so it's technically I think peal um but so it breaks up into this three carbon structure um versus when we look at um three uh C4 um it has to do with that there's going to be a four carbon structure um and so it like kind of brings it in as some other thing so it regenerates it and the reason why we would need this is because of the fact that in Aid conditions um in the uh cytool sorry in the the leaf um we're going to have the um the stamata not to be confused with sha the stamata these little pores and so the guard cells when it gets hot are going to close and so it decreases the amount of um carbon dioxide that can come in because because we of course are losing that um that access point um and so C4 is going to be the adaptation that we're going to find in Aid conditions um Can plants would be those that are going to use different organic molecules um and so at night um like a cactus is going to open up its stata at night so that it doesn't lose all of its water during the day um and so it can then uh Bond it can fix all those uh carbons in the form of um organic MO ules and organic acids and then during the day when there's the sunlight present that's when it releases the carbon from those organic molecules so it's able to keep it theod close and so the fitness would be that those individuals that live in this warmer environment have adapted and found a way to modify the C3 C4 C plant okay um in terms of specifics of the Calvin cycle should we get the big picture or should we know the step- byep again big picture Okay carbon dioxide is binding is getting fixed okay we then are going to use some ATP some n D pH to reduce um in case you don't remember reduction um is like oil rig right oxidation is loss of electrons reduction is gain um so our carbon is going to gain electrons in the form of nadph um see right here it releases it and then I'm going to release carbon dioxide and then the last step is just regeneration or rearrangement um so just remembering fixation reduction rearrangement we start with carbon dioxide I use nine ATP six nphs and I make one g3p and it's easy remember because there's three carbons in carbon dioxide and there's three carbons in one g3p so again it's a the same amount going in as out um someone else said should we memorize the amount of each product um again they're probably going to give you a diagram um but having a general idea to understand oh wow there's more atps made than nadph hm that must be why we have to go through the cyclic electron flow um so kind of keeping those kind of things in mind okay so I think I've answered all the questions on the chat um so multiple choice question chemical reaction for photosynthesis here we see 6 CO2 plus 12 H2O plus light energy gives us glucose plus Oxygen Plus water if the input of water was labeled with the radioactive isotope of oxygen then the oxygen gas released as the reaction precedes is labeled with O2 so that's saying that this issue over here um is going to be labeled I'm sorry that this O2 right here um is coming from this W is what they're saying which the foll is a likely explanation so during the light reactions water is split well yeah at photosystem 2 I saw that my water got split releasing those electrons um and the hydrogen's combine with the H2 with the CO2 no the CO2 was in the Calvin cycle so that's not right and oxygen gas is released which that one is true because the water gets split releasing the oxygen so during the light reactions water split true removing electrons and protons and the oxygen gas is released that one's also true so so far I think the answer is B but let's just double check read through our other choices make sure we're good During the Calvin cycle water is split no that happened during the light reactions regenerating nadph to nad+ um no way um an oxygen gas is released again oxygen release was during the light reactions during Cal cycle water split again no hydrogen atoms are added the intermediates of sugar no and oxygen gas release again no so a lot of times some of these answer choices might have things that are right but then also things that are wrong so don't get distracted when you look at your multiple choice questions kind of look through them if you need to make yourself some check marks as you go through it making sure things that are right or wrong um until you can kind of go back to figure out well which one is my right answer or at Le can help you to narrow it down like oh A and B both sound right and then you can have a 50/50 shot instead of a 25% chance um and yes there's always only four answer choices on your multiple choice so the answer is B so in experiments measure rate of respiration in crickets and mice at 10 degrees versus 25 degrees would formed with respirometer appar that measures changes in gas volume respirometer was measured in milliliters of oxygen consume per gram of organism over several five-minute trials and the following data was obtained according to the data the mice at 10 Dees demonstrated greater oxygen consumption per gram of tissue than the mice at 25 degrees this is likely explained by which of the following statements okay so we have to think first second what's the difference between a mouse and a cricket well a mouse is a um endotherm which means that it has going to be a warm-blooded organism it's going to regulate its own temperature using metabolism um versus a Cricut is going to be an ectotherm Ecto th meaning that it is a cold blooded organism it uses the environment to regulate its temperature um you may have done an experiment like this looking at um your uh peas and you put the peas in warm temperature versus cold temperature just to see what was going to happen in terms of which one respir more I you use a little respirometer you may have done the experiment you may not have Okay anyway so we need to figure out well why would it respirate more at 10° than 25° so if we look through answer choices a says the mice at 10° has at a higher rate of ATP production than mice at 25° well if I'm going through more respiration right I've got a higher respiration rate that means that there's more ATP that's being synthesized um because of the fact that I went through the process of Cellar respiration more frequently so so far I think a sounds right B the mice at 10° had lower metabolic rate than the mice at 25 degrees well if it had a lower metabolic rate then I wouldn't see as much oxygen being consumed because there would be lower rate so that's not true C the mice at 25° weighed less than the mice at 10° hm that sounds logical but the an the question told us that it was per gram of organism which means that they've already accounted for maybe a difference in the the weights and the mice 25 degrees was more active than the mice at 10 Dees um and if it was more active it would have needed to respirate more okay so a is our answer um does AP Bio cover the biology of skin coloration melanin ET Etc um some teachers do bring that in as like different forms of natural selection and adaptations that might have occurred um I know hhmi biointeractive has a activity that they do there was like a video and a whole activity they do in terms of the biology of skin coloration um because uh the melanin um historically kind of looking evolutionarily um is found kind of at the equator regions individuals that live more in the equator have higher amounts of melanin because the melanin is going to break down the UV radiation um which is why they're darker complexion versus individuals that kind of lived up at the poles um or lighter complexion and they had like the red hair I believe um and that was because of the uh there wasn't direct radiation from the UV okay so looking at a for response we've got question 2021 number three the hypothesized that there was a plant compound uh reol um improved mitochondrial function to test hypothesis they dissolve this chemical into DMSO the solution passes through cell membranes um they add the solution to the different muscle cells in a nutrient-rich solution that contains glucose they measure the ATP production at several time points after the addition of the solution and find an increase in ATP production by the muscle cells um so part A is asking us to describe the primary uh Advantage for the cells using aerobic respiration over fermentation now we didn't mention fermentation so let's talk about fermentation real fast about this um so fermentation is going through the process that takes place if the uh pyu is unable able to get into mitochondria or if there is no mitochondria for the pyu to go into and so when you're talking about fermentation we go through glycolysis first and then we go through the process of fermentation fermentation will regenerate the NAD plus um so if you remember there was the NAD plus that took the electrons when you broke down the G the glucose and glycolysis and it held those electrons as nadh taking them over to electron transport chain well if they can't get to electron transfer chain I've got too many nadh's and I don't have any NAD pluses which means that I'm not going to be able to go through glycolysis which is a problem um and so when I do fermentation I only go through glycolysis there was two molecules of ATP that was made in glycolysis uh that's not a lot versus aerobic respiration is going to go through glycolysis making two crab cycle making two and then goes through oxid phosphorilation and in ch osmosis step there's I think 32 to 34 is um that are synthesized and so we see that there is more um a ATP that synthesize in aerobic respiration than in fermentation so more ATP per glucose is produced by aerobic respiration as a reminder this is actually one of the newer free response questions and so they always ask you an a question about the biology can you explain the biology of it and so this is a straight biology question why is aerobic respiration better than fermentation or what's the advantage of one or the other so Part B says to identify an appropriate negative control okay so now we're looking at uh experimental uh design Ian an understanding what is a negative control and what is the point of it okay so in terms of negative control this is going to be something that is uh allowing us to she see does our um independent variable actually have an effect so we're just basically isolating the variable to determine was that actually the thing that did what we think it did in the experiment so what is the negative control for the experiment and that would allow research to conclude that ATP is produced in response to the reciprocal treatment well as a reminder the recipro is in DMSO so was it the DMSO that caused the effect or was it the recipal or what however you say the word well I don't know so I need to test it again without the chemical and so I would say Okay run it without the recipro or run it so that it has just the DMSO alone okay so I can take out the recipo and say okay what would happen when the independent variable of the reol isn't there okay um so part C predict the effect on short-term ATP production when it's treated in a medium that lacks glucose glucose wasn't that what I started glycosis with well if I don't have any glucose can I go through glycolysis no I don't have any glucose so I would expect there to be no ATP made but in case you've gone through this with your classes you might know okay well the glucose isn't the only thing that's broken down we also can break down fats um and so those different fats will be broken down just like two carbon uh structures that go straight into crab cycle we can break down our proteins the amino acids get broken down two different ways and they end up going again into the CB cycle um and so I could also say that there is less ATP produced um and so no ATP produced or less ATP produced and then Part D the researcher found that this stimulated the different components of the electron transport chain um so if they then of course um had U sorry they said that the Recio would would increase oxygen consumption and we need to justify that well why would I see more oxygen consumed oxygen is my final electron acceptor and so if this is stimulating electron transport chain that means I'm going to need more oxygen to take the electrons in electron transport chain which means that I'm going to see can that increase in that oxygen consumption so more electrons can be transferred so that more oxygen is required as the final electronic sceptor okay so last fq and then we are done um so nony electron flow are electron flow are two major Pathways of light dependent reaction in photosynthesis in non-cyclic electron flow electron pass from photosystem 2 um then the components electron transport chain then photos system one finally reducing nadp plus to nadph in cyclic flow they cycle back to photosystem 2 um sorry photos system one and then the components electron transport CH okay so what you're seeing here is that this right here is cyclic electron flow it goes to the ferrodoxin and instead of going over here to nadp+ it comes back into the electron transport chain okay so this diagram confused some students on the exam last year and I think it's BEC that is not updated I should have said last year I'm sorry it is on last year's exam 2023 number I think four I didn't update this I'm sorry um and so the confused students last year because of the fact that they'd never seen this diagram before so if you see a diagram that's confusing just take a beat and just make sure that you're following what's happening say okay it talks about this okay cool I know that part okay and then see what the difference is oh they're cycling well this is my CYCC and so really make sure that you understand what the diagram is saying so part A again a always talks about the biology what is the biology here describe the role of chlorophyll in the photosystems of plant cells chlorophyll chlorophyll oh the chlorophyll is the pigment and so it's going to absorb the solar radiation um it's then going to be the site where we uh saw the breaking of that water molecule to release the electrons from water um you talk about absorbing the energy from light um and so you could say Okay chlorophyll captures absorbs light energy chlorophyll receives the electrons from the water it receives the electron from electron transer chain or it receives electrons um to the electron CH so that what that's saying is okay number one we see the electrons right here going electron transer again use your diagrams it shows you the electrons going in okay um you could also talk about that this electron went over into photos system one so that was the other place where we saw it and then see the electron being generated again okay so Part B says based on figure one here's figure one explain why an increase in the ratio of nadph to NAD uh plus p+ will cause an increase in the flow of electrons through the cyclic plane so if I have a lot of nadph that means it's holding the electrons and there's not a lot of nadp+ to accept those electrons so that forces it to go through cyclic flow I'm unable to see nadp plus taking that electron um so explain why the increase would cause an increase in flow of electrons because there was less nadp+ to absorb that electron or to take the electron or to carry the electron um so less or no NP uh to accept the electrons so electrons pass to the cyclic pathway or pass from ferrodoxin to the cytochrome complex instead use your diagram to explain um now part C and Part D didn't actually have to do with unit three um so I cut them if you really want to know it's about um biomass and how the biomass would change um in a a certain environment so if there's any questions that you have about unit 3 you can go ahead and put those into the the chat um while I kind of kill some time while I wait for you know y'all to catch up with me um so don't forget um I am posting every day Monday through Friday on my Instagram um to get you ready for the exam I think yesterday on Friday we did uh 3.5 so we're currently going to be doing 3.6 on Monday um I also uh post those same questions on my Tik Tok and I have a countdown on my Tik Tok not like you really want to see a count down to the exam but just in case you do um and then you already know about the YouTube because you are here watching this live stream or at least you're watching the recording of it so does anyone have any questions before I log off um going once going twice um so it doesn't look like anybody has any questions