all right good afternoon ap bio live welcome to your first of eight reviews over the next two weeks preparing for your exam coming up either in may june or july so grab a chair get a notebook grab something to eat and um let's kind of get ready get those brain cells fired up as we get ready to review and so again my name is mr monsoor or some people call me columbian bio and let's get ready to rock and roll so just a couple things um and what in terms of what we're gonna learn and so what i want to kind of talk about first is the overview of the exam and so the whole point of this review is not to re-teach the material but just to kind of give you little snippets uh to get you ready for the exam so before we do that let's just do an overview of the three exams and days so the first one the first ap exam administration will be friday may 14 2021 so about a couple weeks from now those of you will be taking on paper at 8 am local local time at your school so good luck on that one if you're taking it on paper uh the second administration will be thursday may 27 2021 at uh 12 p.m eastern daylight time it'll be digital in school or at home and then ap bio exam administration three that'll be friday june 11th uh 2021 at 12 p.m uh either digital and homer at school so again just kind of a quick review if you're not sure of which test you're taking you may want to check with your teacher or you may want to check with your ap coordinator and so just a reminder uh with the test it's going to be 60 multiple choice questions in one hour and 30 minutes which is about half of your exam score and the second uh section will be six questions six frqs in one hour and 30 minutes and that's also 50 of your exam sore so again make sure you know if you're not quite sure you know i'm taking the exam i don't know when you may want to kind of check with your teacher or your ap coordinator and kind of figure it out because it's kind of important so again um what the whole point of these reviews is again to not re-teach all of this material we've done these ap dailies you may remember me from such classics as cell communication regulation uh respiration and probably my greatest hit photosynthesis who could forget photosynthesis but anyways what each review is going to do is we're going to go through a unit and kind of pick out what we think are the main topics so for example what we're going to talk about today properties of water right water's wet right i just blew up the internet with that question that was very popular one last year talk about structure and function of biological molecules proteins proteins they do all the work dna gets all the glory cell structure and function you know prokaryotes eukaryotes what does it mean to uh control the cell like the nucleus or to be a golgi uh cell size you know i've got these three dice here right well i got one dye and some blocks but how does uh cell size you know allow for moving materials tonicity and osmoregulation sounds like a boy band tonicity you know don't go breaking my water or don't go like moving my water something along those lines and then of course mechanisms of transport so each ap live review is going to kind of be built around these ideas of particular topics and task verbs what you need to be able to do so again if you're expecting like a complete review of the entire course you really need to also go back to ap dailies and you're also going to notice something here i've got a qr code and i've got a url at the bottom these are for you to provide feedback or ask questions and so along the way through the powerpoint i will give you the opportunity to hit pause because this is live right now or if you're watching it down the road on demand whatever we'll call that um you have the ability to submit questions so the tiny url um you'll have access to that it'll take you to a google doc if you've got your cell phone right that qr code if you scan that that'll take you to the google doc or google form and you'll be able to ask questions you get any kind of feedback for me you know if i kind of mispronounce something which i will if i start off kind of rough which i think i already did but it's all good feel free to send in some feedback i like good constructive criticism but also if you got questions you're like mr monsoor i don't understand water potential put that in there and we'll be sure to try to address in the next video and also if you want to shout out feel free to put that in there so anyways that's kind of the overview of the whole point of these reviews but but mainly we're going to focus on the content so unless there's any like well if my students were here i'd be like are there any questions i'm looking around my classroom no questions let's begin with our first topic which is properties of water so let's review so talk about properties of water uh the first question i'd ask yourself why water if you look at the course it starts out with water and so really why we need to talk about water is that water is like every living system depends on water and that structure of water right so i've got these little magnets here of these water molecules right i'm trying not to block out my face you guys can see those but you may have seen these before in class but why is water so important so right so we're talking about the structure of water that idea of polarity right the importance of polarity hydrogen bondings cohesion and adhesion so that's kind of the first topic 1.1 so again if you feel like you know this topic that's fine but if some questions pop up make sure you put them in that google form also please refer to ap daily 1.1 for more detailed information and again we tried to select topics that we thought you know kind of challenge students so that's my little check mark saying you should be good on these so let's uh let's look at an example so i've got a image here that i created on my own and so if we look here it says describe the bond that there was pointing to and so when you're doing those task verbs you have like things like identify i could say identify the bond but this is a describing so describe the bond the arrow's pointing to let me put my arrow up so at least you know what i'm talking about so let me get to my arrow so there's that arrow it's pointing to that dotted line so describe that bond and so you may you know in a multiple choice or or some kind of frq you know you see this term described so we know hopefully that that is a hydrogen bond and how would you describe that so maybe pause if you're in class right talking to your friends like what is that hydrogen bond i remember this we did back in august but really we're talking about hydrogen bonds i'm going to put this up here my little molecules the red and the white to represent water right so we see that on this bond we've got red i'm going to try to point to it which is the oxygen without hiding my face and we've got the white which represents the hydrogen so red is oxygen white is hydrogen well if we know anything about a hydrogen bond we know it's a non-convol non-covalent i already mispronounced something so put down the feedback it's a non-covalent attraction and it's based on an unequal unequal charge or unequal sharing and so that's a hydrogen bond so again we talk about hydrogen bonds hydrogen bonds are important because they do give water its unique properties so these hydrogen bonds base the polarity so hopefully you can describe that a hydrogen bond is unequal sharing it's not covalent and it occurs between the water molecules there so again maybe a good thing to draw that out hit the pause button down there kind of talk it out next i have another image that may be helpful is that i've got an arrow pointing and so i've got air i've got what what's in blue represents water and then i've got like a i've got like a close-up of like you're zooming in on some water right and so describe the concept that's being represented in the image above well let's see i've got four of them here i'm gonna try to put four of them together again my models have limitations look at that model i don't know if i could be on a show maybe it could be a hand model but anyways this water mole model is is describing a process or describing a concept so what concept is represented image so let's think here we've got some hydrogens i see the bonding between the hydrogen and the oxygen we've got water there so any guesses any guesses anybody in my classroom anybody anybody we're gonna pretend my students are here all their hands are up i don't know who to call on all right you go ahead and what is your answer and everybody say in unison surface tension right so hopefully you've talked about surface tension again if you haven't refer back to the ap dailies but surface tension is a type of cohesion and so if if you saw in the beginning of the presentation i had cohesion and adhesion cohesion is water sticking to water essentially so i've got cohesion represented there adhesion is water's ability to stick to a different surface right as long as it's polar so this concept here is surface tension and so that the importance of surface tension is if you've ever been out to a pond right you might see those insects able to walk on water well it's because surface tension they don't have the ability they're not breaking those bonds and so that is a very important property of water is that ability of surface tension but describing the process you would say because of the unequal sharing right because of those multiple hydrogen bonds the insect is not able to break through that surface of water and there's some other properties of water that i don't have in here such as adhesion which i mentioned earlier and these all tie back into transpiration so again thinking about water why is water important all metabolic processes that are important for us to survive occur in water right dehydration synthesis hydrolysis so that's why it's really important that you understand a basic understanding of water because water is going to travel throughout the course so all right so as we talk about water we're now going to jump into the next topic which is 1.5 which is structure and function of macromolecules hopefully your understanding is that when you're when you're learning ap bio it's kind of like you're weaving a basket how does everything go together so i know about the water now i go to the structure and function these macromolecules how do they go together right and so when we look at 1.5 we decided margaret and i that directionality and then the four elements of protein structure were really important and again if these are concepts that you need review for check out 1.5 ap daily again that's going to that's going to be helpful so we talk about directionality in again there's my check mark telling you these highlights these are the things that you need to know so let's kind of look at an example get a little ahead of myself here i apologize you guys are making me nervous all like 10 000 of you on there or whatever but you guys are awesome thank you for being here again so we talk about directionality so when we talk about directionality this is an example of directionality in dna and why i picked this one is because i find that my students still struggle with directionality i like to think that i teach it well they're all shaking their heads no well if they were here they'd all be shaking their heads no but anyways directionality is really important directionality is also really important when we get into units six when we look at dna and rna synthesis right and the fact that um nucleotides can only be added to like a certain like th that three end and so let me hit my button here so we look at directionality i'm gonna put my arrows here you've got this three in and you've got this five end and so that double that dna double helix right if you remember it's anti-parallel which will come up a little bit later but it's but the directionality is important for the bonding and when you do when you uh do dna replication and when rna is uh synthesized and so again knowing like 3n and 5n right which way it's built so if my dna is running in this sequence the mrna has to be run in this sequence and that's very important for that bonding of those nucleotides so again if you've got questions about directionality of dna put in the uh put it in the google form but again next week i will also be talking about directionality but again this is one of those ones that i feel that students really struggle on so again got the little pause button down there maybe hit pause you know write down a question why is this important but again it's important for synthesis the other important part the other uh major concept in 1.5 that i think is really important is this structure and function but this level of primary structure of protein structure excuse me protein structure there is a primary level but it's protein structure and so we talk about proteins really understanding the protein structure and the directionality is important especially when you get we start talking about things like mutations and those kind of things so i've got this thing called a bendaroo i've got a couple benderoos here so it's a bendaroo right i don't want to cover my face it's just like a really big piece of like styrofoam it's got a piece of metal in it so i can bend it so when we're looking at protein structure we've got a primary this is my primary again this is a model all models have limitations but if we remember when you may have learned about structure and function macromolecules this would be made up of a sequence of amino acids right we've got these carboxyl terminus it's linear we've got these peptide bonds right you've got dipeptides and so on and polypeptide so this is a really long primary structure of a protein right and so when we're talking about proteins we need to talk about folding so we've got our primary level but because but because of the interaction of those hydrogens which we're going to talk which we've already talked about the importance of hydrogens we've talked about water they can form a secondary structure so i'm going to start to my hydrogens are starting to interact so i'm going to make this is an alpha helix right so a little helical structure maybe i'm going to throw in some beta sheets hopefully you guys i feel like i'm making balloon animals you guys are like it does seem like a circus no i'm just kidding so there's helix beta sheet let's throw in a couple more let me do a little twist here i'm gonna do another helix all this kind of craziness going on and kind of kind of put together so this secondary structure right kind of keep with that this would be because of those that hydrogen bonding it's because those hydrogen bonds you form the secondary structure right and so structure determines functions so these hydrogen bonds how they're interacting and this is important when we get into tertiary so tertiary i'm gonna have to start it to fold inward all right we're gonna have it fold inward and this is very important because we're talking about inward right some of these hydrogen bonds are going to kind of go towards the middle right and some of these or excuse me i got to step back real quick i need to talk about r groups the reason that the tertiary structure forms is because there's these r groups and these international in these interactions of these r groups will lead to this folding so i kind of skipped ahead there so the r groups based on their chemistry some of those r groups because they're hydrophobic water fearing will fold inward because some of those r groups are hydrophilic they're going to be kind of towards the outside here so i'm going to make sure i clarify that so tertiary group folding inward hydrophobic phobic fearing water loving hydrophilic will be towards the outside so there's that tertiary structure so we have primary straight sequence secondary was that helix and the beta sheet this is my tertiary structure so here's my tertiary structure now we've got this quaternary and this quaternary structure is assembled subunits so let's pretend my blue one here this is a sub unit i'm gonna make another subunit kind of quick so there's a helix um a beta sheet trying not to cover up my face too much or you guys like please cover up your face no mice that's what my students would say it's all right let's all pretend they're there so here we go another folding of a bendaroo so here's the tertiary structure right tertiary these multiple subunits they interact it's not a very pretty protein but it works right but again what's important about what's important about this is the chemistry or the way that those r groups those hydrophobic ones are folding towards the inside of the molecule and those hydrophilic ones are going gonna be kind of sticking on the outside and why this is important you're like all right mr monsoor why why do we care about protein structure because later on when you learn about mutations and say you have a mutation i don't want to get too far ahead because i don't want to take away from anybody's presentation change the structure change the function and so what you could actually do is cause some of some changing in this folding so hopefully that made sense um again if i said something that i went too fast do something please put in the google form and i'll readdress it but so again just one more time primary structure i'm going to do a quick helix some folding another helix secondary tertiary multiples quaternary and again these are important because structure determines function so i may have spent a little too much time on that but i think it's important so pause here if you've got some question overwhelmed you type in something in the google form so let's let's a little practice here so here's a practice question um and so i will read it to you so this is developing and just finding a scientific argument you got to use evidence and so these arguments right these are these require a little more thought than maybe just an identify so a mutation results in the production of a version of a small protein that is only 105 amino acids long as shown in figure two five of the hydrophobic hydrophobics important so you gotta think to yourself hydrophobic water fearing right they're gonna be they should be folding towards the inside right or in this case there's a primary structure which is not showing the folding but five of the hydrophobic amino acids are missing from one end of the chain which of the flying best depicts the tertiary structure of those two proteins of water so that tertiary structure is that really complex structure so if we look at figure one and figure two if we look at figure one it's a primary structure you see the black dots hydrophobics are on the end right again this is the primary structure there's no folding here and then figure two you can see where you've lost one of those ends so if we look at our options we've got a b c and d well if you were paying attention to the tertiary structure c and d you could probably eliminate right away because i'm looking at c and d and it's like wait original protein what's this wavy thing kristen show me folding or excuse me mr monsoor and then that original protein and mutated but let's look at a and b you've got the original protein for a and the original protein for b now if you go back up to the question it says hydrophobic those black dots are hydrophobic would they be sticking towards the outside into the solution no they would not and so really just just being understanding okay how does this biology work if they're hydrophobic or falling inside that would hopefully get you to a now let me unclick a real quick because you can see where that mutated protein is do you see that little nub that little dot that's sticking up that is one of your hydrophilic ones of course it's going to stick up because right it's water loving so we're hydrophilic so again we've got hydrophobic hydrophilic protein structure is important because again a change in structure leaves a change in function and this will be later on down the road so all right so those are our proteins so that's kind of unit one stuff um there is some other material in unit one that you may find that you may be struggling with go back and watch the ap dailies but the water and the structure of proteins will be found throughout the rest of the course so let's move on to unit two which is cell structure and function we all love cells however what i find with my students and nothing against my students i love them heart out to you but uh they can correctly identify an organelle but they fail to correctly describe its function so if we're looking at the highlights for structure and function right you've got these subcellular components right that's important structural feature of the cell allows the capture store and use energy so that's going to be like your mitochondrial chloroplast but misconceptions or what i should may have called these challenges now is that they can correctly identify an organelle but like what's its function and i'll ask them what's its function i look out they'll understand they all bobble head and then i'm like then i ask a question and it's just crickets but anyways i love them so i'm just they know it is so there's a check there's your highlights there's your misconceptions so again the biggest thing is being able to identify an organelle but you got to be able to describe its function so again ap daily 2.2 for more detailed information on that so let's look at an example of this so can you correctly identify an organelle and accurately describe its function that's great nucleus does you know this is the nucleus this is the golgi this is the er but accurately describe its function and better yet if i when i review this with my students i would have them trace the pathway from the nucleus out to the cell membrane and this might be a good time for you to pause the video if you're you know watching this on youtube but can you correctly trace that pathway right so you have material made in nucleus right all right if it's i'm not going to get into too much of this right now because that'll be a later unit then it's going to be processed and packaged on the er whether it's the rough er smoothie r it gets the golgi and then from the gold you'll be exported out that's the big thing and it's great that you know what they are but can you go from point a to point b and so again if you're reviewing it's again it's one thing to identify but you really need to know the functions but also what happens if you change the structure and how that you know how that can lead to a change in the function of that organelle so again um pause the video list many organelles as you can but hopefully you know what their functions are and so um that's kind of that's that's the important part of topic 2.2 but again going from nucleus to cell membrane i would i would encourage you if you can do that i think you have a good grasp of it so but let's do a little practice real quick so i've got another topic too this is making a claim making claims are important often when making a claim you're going to have to look at some information so in an experiment researchers provided a radio-labeled amino acid to leading plant cells after one hour the researchers determined the amount of amino acid that was in each of the compartments the results the experiment represent the table so if i'm seeing this the first thing i'm going to do is i'm going to look at this table okay i've got these numbers i've got 2.1 2.7 1.91 okay what's sticking out i got 2.7 in the mitochondria and i've got one in the cytosol that nucleus and er they're pretty similar so which of the fine conclusions it's a conclusion this is where it comes into making a claim about the material is best supported by the results so it's mostly incorporating nucleic acids for a when nucleic acids a nucleus it's 2.1 that's not mostly because it's less than 2.7 it's mostly incorporated into proteins that regulate management metabolic reactions metabolic reactions metabolism okay cell respiration photosynthesis something along those lines it was mostly incorporated into lipids lipids are fat surrounding surrounding environment that might be i'm looking up there that might i'm not sure if there's anything up there maybe the cytosol could be an argument doubtful it's mostly incorporated carbohydrates to form protective structure outside the cells well really if we're talking about what the 2.7 that's the most and we're talking about metabolic reactions most incorporated that's your correct answer there and so you could justify the fact that the reason that the 2.7 why there is so much radio-labeled amino acids and that mitochondria is because they're regulating metabolic reactions so that's how you know making a claim is really important you need to look at the data to justify justify your response so all right i know i'm kind of going quick here i just got to check time because i want to make sure we get through everything and so i think 2.1 2.2 the flow excuse me 2.2 the flow of the molecules that should be pretty good i think you guys usually have a pretty or everybody has a solid foundation but let's talk about cell size and this is where students struggle i struggle with this um and then we're talking about size to cells calculating surface area volume ratio look at your formula sheet because of time i'm not going to be doing the math on here but i'm going to give you kind of what i tell my students and then misconception i find this that larger cells are more efficient bigger is better not in biology bigger is not better but again i'd like you to refer to 2.3 for more detailed information if you do have some questions so let's kind of let's let's let's kind of look at an example so why can cells only get so large so we're going to sit here and ponder right i'm going to take a breather why do cells only get so large hmm let's think here pause it maybe think about it well cells can only get so large because stuff's got to move in and stuff's got to move out and so if you think about unicellular organisms so if you think even like prokaryotic organisms like a bacteria they're not really large i mean you need a microscope to see them and if you think about protists you think about your own cells they can only get so large because of surface area volume ratio because of that movement of materials going back and forth that really does kind of restrict how large cells can get can get because stuff has to move in it's going to get processed and stuff has to move out and so oxygen nutrients moving in waste and carbon dioxide moving out so why can cells only get so large because of what we're going to practice with surface area to volume ratio so we're going to perform some mathematical mathematical calculations again i would encourage you to look at your formula sheet here what i often do with my students is that we will go through and i try to do at least one math problem perf found on the formula sheet so we've got simple cuboidal epithelial cells line the ducts of certain human exocrine glands various materials are transported in or out by diffusion and we'll talk about diffusion a little bit later which of the cube shape would most would be most efficient in removing waste by diffusion so before i get to that what i will often do is that when i do this activity i show my student three different sizes of cubes i've got a dice or a die excuse me a basic wooden block trying not to block i'm blocking out my face and then i've got a larger cube so let me kind of do this without dropping them so i've got these cubes here right and i'm going to ask them okay of these three if i need to get something to the middle of that cell what's which cell is going to be able to get stuff to the middle first oh of course the smaller one right because the smaller one the die it has less kind of area it's going to be more efficient because it doesn't have to go as far and so when you're looking at these kind of questions when you're presented with a cube right so you've got a b c and d i've only got three here right which which cube shape volume would be the most efficient removing waste by diffusion you want to look at the one that has the greatest surface area to volume ratio so surface area is six to one or five to one or four to one something along those lines and so if you do do calculate out the math it is going to be um letter a it ten it's gonna be the smallest cube because it's not gonna take as long to get from point a to point b on that cube so if i want to get to the middle of this die right i could i don't have to go so far however if i got to get the middle of this cube it's going to take me a while right so if i have to go from the outside to the inside it's going to take a lot longer in this one than it will again i'm trying to do this in this one right so this will be more efficient and again because of time and having the cover material if you go to the ap daily 2.3 there is um there are some problems worked out but also as you can see on my source at the bottom again the progress checks are going to be your best friend maybe not your best friend but they're going to be pretty good help so anyways again i know i'm talking fast but i want to make sure that you get the most out of this as you can so let me kind of move on there so when we get past this idea of surgery volume ratio again when we're talking about getting to the cell membrane we need to go back to water right water we started out in the first section now we need to kind of talk about how water moves and tunisian osmo regulation is very important because that is really what is going to kind of deal with homeostasis and a cell's ability to function so the highlights different ways describe relative tonicity osmoregulation how does it contribute to health and survival organisms again this might be good i don't have a pause button here but this might be a good place to pause and write down some terms you're not familiar with and maybe just kind of like look up the definitions and i'm going to provide some of those there are some misconceptions um when we talk about tennessee as a regulation i should have probably put that first but movement of water like hyper hypo and iso which i'm going to talk about but also with this one it's your ability to make graphs and so i will do a quick another quick but i will review with you how to do graphs but what a student should be able to do what you should be able to do is you should be able to label the independent dependent variables with units you need to be able to plot data points with appropriate scaling and correctly represent data in a question and we're going to talk about that a little bit and as you progress through the eight ap lives you are going to see like we're gonna build on that you know applying error bars and those kind of things and then again with movement of water hyper hypo and iso so again i would encourage you encourage you one more time encourage you to refer to ap daily 2.8 because tennis tunisian osmo regulation i struggle with it um at times when i'm at the board and i'm trying to remember which way is water moving i'm dr i'm drawing out um i'm drawing out cells that are in hypotonic and isotonic solutions so i would encourage you that again i've said it four times you get the idea so it's like a broken record right now i apologize all right so let's there's our check marks that's the good these are misconceptions or your challenges so let's look at an example i got some examples here so can you explain the water movement so i've got you can hit pause here if you want to explain isotonic solution hypotonic solution hypertonic solution and so if we look at our first one and again if you want to pause and write your own that's isotonic solution and the water is moving back and forth right and so i often tell my students this is you know this is kind of like an equal dynamic equilibrium the water doesn't necessarily stop so in isotonic solution it's going to go back and forth right flow back and forth right because of the movement hypotonic water's moving in and hypo and hyper refer to the environment in this situation so i place a cell in a hypotonic solution right there's less solute in the environment so the water is going to move from what from towards more solute right which would happen to be inside the cell hypertonic right you're losing water and so i place a plants on a hypertonic solution it's going to lose water so when i kind of like use an example for my students so like for isotonic not so much but if you ever go to the grocery store right and you're walking in whatever your grocery store is right and suddenly the sprinklers come on you're like why are they watering these plants they're like there's some roots there but they're not growing the idea is i'm just having this vision now of me walking through the grocery store but anyways i digress in a hypotonic solution right as that water right gets onto those plants the water is going to move in those cells are going to swell up right and you're going to increase some pressure and it's going to make them look fresh right nobody wants to buy you know lettuce that doesn't look fresh or you know other vegetables that or fruits that don't mostly vegetables don't look fresh so that water moves in it swells up right it looks it looks awesome looks like it's ready like it's just fresh picked hypert so that's that situation hypertonic solutions this explains like i kind of live in a rural area and so in the winter when it snows and some of you may not have snow so i understand that but we cannot put salt down near agricultural areas often so if you've got a lot of salt in the road in the winter and for some reason that salt gets into the field springtime comes and that salt dissolves because water is polar right has the ability to you know dissolve break up that same chloride it's going to get in that soil right and so instead of you know your plant but that soil is salty so you know you've created a hypertonic solution and so um salting the fields is not a good thing so if we go back to can you explain the water movement well isotonic solution it's moving back and forth okay hypotonic hypo it's going to move in moving because water moves from higher water potential to lower water potential but also you're going to look for where where the solute is and then a hypertonic right it's going to move out and i could not find um a good picture of red blood cells so i made my own out of a material that i don't know if i'm allowed to say because of copyright so here's a red blood cell i'm going to kind of zoom in a little bit these are not like those cake pops i can't eat it so this is a red blood cell right it's got a nice little donut shape right so this is a red blood cell what kind of solution anybody anybody in my class if they were here yes this would be isotonic so this red blood cell would be an isotonic solution water moving back and forth my body would be in homeostasis i would be just swell maybe not swell but i would be good so this would be a red blood cell in an isotonic solution right so then that disappears and then i decide to put my red blood cells i inject i get it i get injected with distilled water bam right distilled water my red blood cell is also one this one definitely looks like a cake pop so what's happened is distilled water no solute right it's all just it's just water pure water well in my red blood cell right there's a certain amount of physiological material in there or material to maintain physiological homeostasis but there's materials are dissolved in there that water's gonna rush in right so here's a red blood cell right water's rushing in it's gonna expand and how this is different is the fact that this red blood cell does not have a cell wall like that plant cells that pressure's going to build up and you know might pop whatever then what if i place it in a hypertonic solution kapow now this is supposed to represent the water leaving right and so it's going to shrivel up right and those red blood cells are going to lose that moisture so and i'm going to change its structure which ultimately changes function so if we look at the three my three plato uh props here isotonic hypotonic hypertonic so if you if you get a question like on the ap exam just draw them out right just draw them out um you're probably not gonna be able to have plato so this looks like a wand of some sort but we're going to stop there but anyways so that's kind of the tunisian osmo regulation kind of give me an idea of how to remember those because i do really think uh i know i struggle with it students struggle with it so i think it's just a good thing to review so let's kind of let's practice a little bit so we're going to practice we're going to do is we're going to practice looking at a graph so when you make graphs so or if you have to make a graph on the exam depending on the exam will determine graph components so the components of a graph include a title correctly labeled axes with units uniform intervals identify lines of bars and trend lines the graph type is based on the type of data and graphs can be used to show trends over time comparisons distributions correlations variability relationships there's a lot there just practice making graphs and determining what type you need just please please please do that and so we've got some data here this is courtesy of kelsey beerus who is an amazing ap biology teacher if he's watching this this is your shout out because i couldn't have come up with this on my own so water potential potato cells was determined in the following manner some of you may have done this you took six groups of potato cores they were measured they were placed in a sucrose solution which again would be your solute the mass of the cores were measured again after 24 hours percent change in mass we're calculating the results are shown in the table so we look at table one we've got molarity we got our percent change in mass and if you're going to notice we've got some positive we've got some negative numbers graph these data on the axes provided i did not provide the axes so i apologize so if you want to pause here draw out a rough sketch it's fine but what they're asking you to do here is to take the data and put it onto a graph and so if you construct a graph this is what it would have looked like wouldn't it be great if that's what you could do in aap bio just said poof there's the graph it doesn't work that way so if you notice on this graph it is going to be a line graph because it is showing change over time and so or excuse me that change over time but it is showing a change in the molarity across the bottom so excuse me that was not time but molarity um percent change in mass so a couple of things i want to point out there is a title you do have your axes labeled so percent change in mass and the molarity of the sucrose and the beaker and so again with the graphing what i often find when i tell my students is when they're looking at trying to figure out where do these variables go dry mix dry stands for dependent is on the responding and that's on the y-axis so dry that's your responding variable that's the one that's changing so that's your percent change in mass mix stands for the manipulated that's what we manipulate that's what we changed and that's on the x-axis so we manipulated um the molarity of the sucrose right so we molip manipulated the molarity so there was a graph you've got you've got good breaks you got nice lines there right you've got everything labeled but we did not answer the question yet and let me go back to the question was what is the molarity of the potato core well it's where it crosses the line and so if you again i know many of us were in situations where we could not do the lab my situation was the same however if you understand the skill and the biology behind it okay so the molarity is going to be where it's not losing or gaining mass it's going to be in dynamic equilibrium it has to be where that line crosses the zero and this happens to be about a point two seven sure but anyway so when you're looking at these kind of thing you know doing graphs you know answer the question asked and so again you can pause here but where i put that circle would be considered the molarity and so and then we're getting into um our last topic which is mechanisms of transport because again i do want to respect your time so we talk about mechanisms of transport and you probably would have talked about these through the course of this unit but the highlights which i'm going to put a check plus is um or check mark excuse me it's passive and active transport do you understand what passive and active transport are and then the movement of large molecules and again i cannot emphasize this enough refer to ap daily 2.9 for more detailed information so those ap dailies will help you do the progress check so let's look at an example and i just have some pictures here to kind of review so if we're going across the screen if i always ask my students like tell me a story what's going on here so if we look at this first one right you have materials they're moving from a high concentration to a low concentration what i would call a concentration gradient right and so if they're moving from high to low right that's not requiring any energy and so if we notice that first set with with the dots they're moving straight across they're not requiring a protein so that's your simple diffusion those are like your small nonpolar molecules like co2o2 right n2 those those molecules can pass right through that lipid layer because of being nonpolar the second box that i have labeled right that requires a help it requires a facilitator right i like to think of myself as a facilitator maybe not at times right kids if they were in here they'd be like no but i am so with this one it requires that protein that's facilitated diffusion for whatever reason that molecule is just structurally different that it cannot pass right through that lipid layer so it's going to use that transport protein there for facilitated diffusion and there's another example to the right of it then we go to um excuse me i gotta make sure i get my mouse in the right spot we go to active transport and we'll talk more about active transport in a later unit the key giveaway for active transport is that it requires energy it's an active process so instead of going down the gradient it's going to go up the gradient so it's like you're going up a gradient you require some energy and so probably the most known one or one that we usually talk about is the sodium potassium pump and so if you look at the image you see that the sodiums which would be represented by the red arrow there's like three on one side but then there's like six on the other well that's going against the gradient and if we look at our potassiums there's two four and there's like five on one side so with active transport right you're going against the grain it's going to require energy to get that moving and so active transport often you'll probably see this in a later unit where you're talking about proton pumps and those kind of things and then my last one is endocytosis and exocytosis and these are movement of large molecules so remember when i said in the beginning with 2.2 right flow of a molecule from the nucleus alpha cell membrane right this is where this comes into play these um structures here phagocytosis which is a type of endocytosis and then exocytosis because cells will sometimes bring materials in for whatever reason they may need it for a metabolic process to destroy it but also where the black arrow is exocytosis that is getting rid of materials so again i would pause that here you know if you're like i don't quite remember these again you know put the question in in the uh in the form for us so that we can look at it so let's look at quick practice here so again we're back to our original graph um let's put everything's labeled right but in this case we want to explain a concept when you explain think of the word because so explain why there is a difference in the percent of mass change of potato cores and different sucrose solutions they're asking like why is there a difference now i know what the molarity is osmolarity i know what it is the potato but why are these differences here so if we look everything above zero is gaining mass water is moving in everything below the zero water is moving out and so again we cross that line so the explanation would be going back to hypertonic hypotonic solutions is the fact that okay well if i place these potato cores in a solution that is you know point uh excuse me where it's gonna where water is gonna move in right it's going to gain mass excuse me my brain shut off for a second but if i put it in a solution that is greater than the osmolarity it's going to lose mass and so that's kind of the explanation because it's losing mass because of its environment so and then again there's just kind of pointing out that data there so again i encourage you to practice making the graphs but as long as you understand what the zero is and what that represents and what happens above the zero what happens below so all right so what should we take away because we're getting close to time so what should we take away um you need to really again i went through that quickly i know it's 45 minutes it's like drinking from a fire hydrant but again you've got plenty of time but you need to review the suggested ap daily videos that i put in there and i think that's really going to be helpful go back and review take progress checks use ap classroom it was designed by a lot of a lot of hard-working people at college board so so please use it practice frqs and focus on those past verbs i have been an ap reader for a long time and it's very frustrating like you are writing amazing answers but you're not answering the prompt what i call atp so make sure when you see those task verbs if it says identify you identify that's a real basic one if it says you know evaluate that requires a little bit more if it says explain explain because describe you know i can describe this as a die right i describe it's got six sides with numbers explain it well it might be a little more complicated and then do not cram you really need to have a plan we have some time here where you know the exam you know you've got a couple weeks if you try to cram there's so much information you may just stress yourself out and so again i know there are some bumps along the road here this is i get it this is live thank you for your patience but any kind of excuse me constructive feedback would be really great is if you go into that qr code scan it or if you go to if you use that link to go in and just kind of leave some feedback or if you got some questions so coming up tomorrow it is the always awesome ever vescent my boss the smartest person i know margaret evans and she will be doing unit 3 cellular energy energetics i cannot say enough good things about her she held this together but anyway she's gonna be talking about things like photosynthesis cell respiration enzymes all that all that fun stuff so she will um be there tomorrow and so again i just want to do a couple shout outs again i appreciate your time taking the 45 or so minutes here to kind of listen to me um again i just want a couple shout outs to lee ferguson and her students there at um texas allen high school matt for new jersey teaching outside of princeton uh tom freeman's classes who i hope are listening there in anaheim but again i also want to thank your ap uap teachers i know you're working hard it has been a tough year um but again i know i've done some bumps in the road here so again if you can leave me some constructive criticism and i also need to thank the the crew at um college board claire and her team that helped us of course spencer who is producing this and is probably ready to be done with me for the day so again i just want to say thank you you guys are awesome uh stay classy ap bio and i will see you in on on wednesday have a good one this is me stein off from room 102 in beautiful tiffin ohio you