hello bisque 130 this is the beginning of recorded lecture 14 we are still in the biological macromolecules chapter 3 uh we talked about carbohydrates and lipids in the last one now we're going to pick up and talk about proteins so for our other macro molecules I started by talking about structure and then we talked about function for proteins I'm going to go in the opposite direction and start by talking about their functions because there are a lot proteins compared to all the other macro molecules in this chapter are capable of doing a ton of different jobs so I'm going to list some of these but you should know as long as this is this is not an exhaustive list proteins do so many things so one of their functions as an example uh is enzymes so yeah here's a a figure from a later chapter we'll get into this in a later later in this quarter but yeah there are many proteins that can help make or break chemical bonds very important job uh but that's not all proteins can also be involved in defense oh here's a slide from bis 132 the other class I uh I may teach depending on what your major is um yeah antibodies part of the immune system these you know y-shaped things are proteins very important part of of immunity so proteins can also be involved in defense proteins can also be involved in transport they can carry uh fats and other things in the bloodstream here's an example of a protein that carries oxygen through your bloodstream very important in getting that oxygen from the lungs to everywhere else in the body where it needs to go proteins can also be involved in structural Integrity so we saw um polysaccharides carbohydrates uh that were involved in structural Integrity in the previous lecture but there are proteins that could do a similar thing there are proteins that give strength to your cartilage and to your fingernails and toenails proteins can be very WR uh proteins can also be involved in muscle contraction again another slide I stole from my bis 132 lectures uh but yeah the way your muscles work involves proteins working off of one another so uh proteins can be involved in this as well and finally again for this list uh proteins can be involved in regulation uh I defined hormones in the key terms uh in the previous recorded lecture uh steroids were examples some steroids were examples of hormon these signaling molecules but proteins can be hormones as well so some hormones are not steroids some hormones like insulin uh the the um process shown here insulin and glucagon are proteins that serve as these sorts of signaling molecules so with all these different um very diverse functions that proteins can have the question should arise how can one type of thing how can one class of Macro Molecule be responsible for all these different very different jobs and the answer has to do with how these things are built proteins are like carbohydrates polymers but instead of being Polymers of individual sugars proteins are polymers of what are called amino acids you know often times abbreviated just as lowercase a period lowercase a period uh but yeah proteins are polymer of amino acids so what do these amino acids look like well this is part of what gives proteins their their magic touch with being able to do all these fun things amino acids come in all shapes and sizes so uh you do not memorize this table but yeah these are the 20 20 commonly used amino acids some are short some are long some are non-polar you know hydrophobic functional groups some are polar some are positively charged some are negatively charged some have big bulky Rings some are more you know straight linear uh some have weird elements like sulfur as part of their functional groups uh yeah so these are really diverse building blocks that's how we can have a you know functionally diverse Macro Molecule doing all these different things uh because it's building blocks are incredibly diverse and again it's a polymer of these things a protein is just a bunch of amino acids strung together to form a larger structure and again you don't need to memorize all the structures or names but you should know there are 20 of them 20 commonly occurring amino acids and yeah they they look different and they do different things they there are different functional groups on these amino acids giving them different chemical properties um it is worth pointing out most proteins at least overall are hydrophilic most proteins will dissolve in water there are some hydrophobic amino acids but on the whole most proteins have enough of the hydrophilic ones to where most proteins uh will dissolve in water so in in our last polymer uh carbohydrates we had a special type of bond that connected the individual units together that was a glycosidic bond when we were talking about carbohydrates we have a similar thing here when we're talking about connecting amino acids amino acids are linked by a type of Cove valent Bond called a peptide bond and uh yep there's an amino acid there's another amino acid here's the peptide bond connecting those together again it's just a calent bond but it's a a special type uh called a peptide bond uh for this reason an an alias of proteins another name that proteins go by uh sometimes is polypeptides which should make sense they are polymers of things connected by peptide bonds so doesn't roll off the tongue as well as protein but polypeptides and proteins are the same thing now proteins have very complicated structures you know sometimes they're drawn you know very cartoony sometimes they're drawn more realistically obviously there's a lot of very specific shape that goes into any protein in order to get this shape the protein has to fold up in a very specific complicated way and to describe this structure we have four dis levels so there are four levels of protein structure the first level appropriately named uh is called primary structure the primary structure of a protein is just the sequence of amino acids so yeah the the key terms say primary structure is the linear sequence of amino acids in a protein so yeah you can describe the primary structure just by listing off you know glycine isoline veine glutamate uh glutamine cysteine cysteine alanine serine ve you just list off the the order of amino acids and that's the primary structure obviously it you know doesn't stop there there there is more complicated structure to this but yeah primary structure is just the sequence of amino acids next we have again appropriately named secondary structure secondary structure are to read from the key terms regular structures the proteins form by intr molecular hydrogen bonding these secondary structures they're not the full shape these secondary structures are common patterns common structural motifs um before we see this let's take a look at these so uh yeah this is something called a beta sheet or a beta pleaded sheet you have a line of amino acids a bit of a loop and another line of amino acids and these two you know ribbons are held together by hydrogen bonds you could have a beta sheet with two sheets you could do three you could do four you could do more but this type of interaction you know just having a sheet and another sheet um is an example of secondary structure very common in proteins the other common second secondary structural element is the alpha Helix where yep line of amino acids here but it sort of winds into a sort of spiral staircase or Helix structure and if we look closely at the interactions here it's hydrogen bonds that is holding this together yeah we we talked about hydrogen bonds a while ago and I said they were the weakest of the three chemical bonds we talked about but there are just so many of these hydrogen bonds across a beta sheet or within an alpha Helix these tend to be pretty pretty durable structures just because there's so many of these hydrogen bonds so to summarize these secondary structural elements these common patterns include the alpha Helix and beta sheets uh importantly held together by hydrogen bonds or or H bonds so again this is not the full three-dimensional structure it's just these common patterns if we want the full three-dimensional structure we go to predictably uh what is called tertiary structure the key terms define tertiary structure as a protein's three-dimensional confirmation including interactions between the secondary structural elements so what holds this thing together again this is the full three-dimensional structure we could see um we could see this um shown in different ways uh you have this very popular ribbon diagram oh there's an alpha Helix there's an alpha Helix there's you know two beta sheets together uh some you know unstructured Loop regions here but yeah we see secondary structural elements this is one way to draw tertiary structure here's a space filling model that's just another way to draw this I think this is probably the more common way to see this the the ribbon and textbooks but yeah these are just different ways of of showing tertiary structure um so what holds this thing together well like this says uh it's held together by interactions but it's a little bit more than that so if we look at what actually holds together this complicated three-dimensional shape we see a lot of familiar things so remember some of these amino acids have negative charges and some of these amino acids have positive charges guess what happens between positive and negative they're going to want to get together they're going to want to form an ionic bond so ionic bond bonds hold together this tertiary structure um so in hydrogen bonds it's not just within the beta sheets or Alpha heles these distant elements can interact and and by hydrogen bonds that holds together this overall shape as well we also have if you're dealing with those special sulfur containing amino acids special connections called disulfide linkages so yeah the you know it's not really showing the beads on the string here but yeah there's an amino acid here an amino acid here an amino acid here an amino acid here if you've got two sulfur containing amino acids even if they're far apart from one one another on the string this disulfide bridge or disulfide linkage is a calent bond that links these two distant parts of the protein together and finally there's a a new type of of interaction something called hydrophobic interactions or hydrophobic exclusion so remember some of these uh amino acids were hydrophilic they want to be facing the outside world they want to be touching water uh but plenty of these amino acids are hydrophobic and don't want anything to do with water at all well these hydrophobic amino acids help the protein maintain its overall three-dimensional shape because these hydrophobic amino acids will fold in such a way that they are in the core of the protein they're hanging out with one another they're tou touching one another they're not touching water so this sort of mutual dislike of water that puts all of these things together in the center or core of the protein is another thing that holds together this structure so this is a a great visual for these things but if you want this listed out tertiary structure is held together by interactions including hydrogen bonds ionic bonds dulfi linkages again this is a type of calent bond not the same thing as a peptide bond just a different type of Cove valent Bond that's very specific here in the tertiary structure and then this hydrophobic exclusion where hydrophobic amino acids fold into the core of the protein now if you have a good memory you may remember I said there were four levels of protein structure and this feels like it should be the end right it's it's the full three-dimensional structure of the thing how could you possibly get more complicated than that well you can in some cases have what is called again predictably it's a lot of key terms but they all have pretty pretty easy names level four quatron structure which the key terms defines as the association of multiple polypeptide subunits in a protein in other words quatron structure is when you have multiple protein units each one has its beginning and end each one of these has you know it its own distinct string of beads and its own tertiary structure quatron structure is when you have multiple things coming together to form a functional protein here's that hemoglobin protein responsible for carrying oxygen in your red blood cells throughout your bloodstream it has a quatron structure it's got you know four distinct polypeptide subunits that come together to form functional hemoglobin uh importantly this is optional so the equater structure exists for some things but not everything has this this Lyme which uh you know I showed a minute ago um it does not have quatron structure it does its job uh by the way this um this breaks down bacterial cell wall you've got this uh in your in your eyes uh for example to uh you know prevent bacterial infections in your eye you've got this enzyme that breaks apart the bacteria cell wall uh yeah this doesn't have any quinary structure at all so this is this is definitely optional not all proteins have quat Ary structure but we're going to see proteins later in the quarter uh that have quite complicated quinary structure so yeah that's our our fourth level of organization and and putting these proteins together now for a protein it's threedimensional shape is absolutely key to its function this lme is only able to bind to bacterial cell wall and break it apart it's only able to do it job because it has this very specific pocket here this very specific curvature everything about its structure is very important for it to do its job you know whether it's breaking down cell wall or carrying oxygen for proteins shape is everything so that means if you lose shape you're going to lose everything you're going to lose the ability uh to do whatever it is you need to do protein denaturation or sometimes it's just called denaturation is defined in the key terms as the loss of shape in a protein and so yeah protein denaturation is when you go from this properly folded all these complicated structures here secondary structural elements properly folded protein to just a string of amino acids losing this complicated structure so what could cause this structure to fall apart well this is actually something you're pretty familiar with whether you know it or not not uh you can easily denature proteins through heat so yeah if you've ever cooked an egg before uh egg has a lot of protein in it especially in the white uh if you heat an egg up uh it is going to denature those proteins and you can visibly watch them go from clean uh from clear to white as these proteins lose uh their shape and they lose their function we don't necessarily care about you know making them lose their function we do care because we're you know we don't want bacteria inside of uh in this egg causing disease uh if we denature the bacterial proteins that's going to make them dead and that's going to make this uh this safer to eat so heat is one way to denature proteins um hey if if there are any um amateur Cooks listening there are other ways to make food uh safe to eat uh heat is you know definitely the most common way to do this but another way uh that will denature proteins is acid uh if you've ever had Ceviche before this is fish or other Seafood um that has been made safe to eat through the application of lime juice or lemon juice or some sort of acid so a low PH uh or high pH uh can also cause protein denaturation and here's kind of an obscure one but another one from the the world of food here is uh messing with salt levels uh so messing with salt content like salt cure Meats um that can also uh cause proteins to denature so yeah all all three of these things can contribute uh to protein denaturation changes in temperature changes in PH changes in salt salt content and yeah this leads to loss of function protein can't do its thing if it doesn't have its shape um this is usually irreversible uh if you take this cooked egg and pop it back in the cold refrigerator again it's not going to turn raw again it's going to stay cooked um yeah this is a this is a no take Backes thing which makes it all the more scary you absolutely do not want your proteins becoming denatured so that's why once again we come back to homeostasis uh preventing denaturation we regulate our temperature or pH or salt content in our cells and the the fluid around our cells we don't want this to happen to us okay we've done carbohydrates we've done lipids we've done proteins last biological macro molecule or should I say molecules uh this last one is going to be two that are kind of put together uh to end out this chapter we are going to talk about deoxy ribonucleic acid and ribbo nucleic acid more commonly known as DNA uh and RNA these things are once again polymers so uh polysaccharides were polymers proteins are polymers DNA and RNA are polymers as well so that means they're a big structure made of a bunch of smaller things linked together in this case DNA and RNA are both Polymers of things called nucleotides so actually before we talk about DNA and RNA and all uh we have to talk about their building blocks we have to talk about what nucleotides are so nucleotide structure again don't have to memorize how to draw this perfectly but there are colorcoded for your convenience here three important structural components to a nucleotide so uh first up something that should look familiar to you this uh you know this ring structure here this is a carbohydrate this is a this is a five carbon sugar so yeah nucleotide structure cons consists of a five carbon sugar um so DNA and RNA are both Polymers of nucleotides they they both use these things there are a couple of small differences between the RNA building blocks and the DNA building blocks and here is one of them the five carbon sugar used by RNA is a sugar called ribos the five carbon sugar used in the nucleotides of DNA is called deoxy ribos uh it's the difference in this one little position right here how are you going to remember which one is which it's right there in the name RNA is ribonucleic acid because it has ribos DNA is deoxy ribonucleic acid because it uses deoxy ribos so there are this is a slight difference between the two building blocks but it's easy to remember cuz it's right there there in their names Okay so we've got our five carbon sugar we also have uh something else that should look familiar to you the phosphate group so we saw phosphate groups earlier when we were talking about phospholipids uh same thing that was true there is true here the phosphate group has a negative charge to it which is going to make these nucleotides hydrophilic it's going to make them negative it's going to make them uh them water loving it's going to make them charged um importantly this phosphate group is attached to the sugar ribos or deoxy ribos at a very specific location it's attached to the fifth carbon so biochemists like to number the carbons so they can be very precise when they talk about things so we would call this carbon 1 Carbon 2 carbon 3 carbon 4 Carbon 5 uh but oops we can't call these carbon 1 2 3 4 5 because we need to number the carbons over here in this third component which we'll get to in just a minute so instead of calling this carbon 1 Carbon 2 carbon 3 carbon 4 Carbon 5 we have to call this carbon One Prime two prime three prime four Prime five Prime the phosphate group is attached very specifically to the five Prime Prime carbon of this five carbon sugar for this reason it is often called the five Prime phosphate referring to which carbon it is attached to might seem like too fiddly of terminology to get into trust me when we talk about DNA structure and function and how this stuff works the the numbers and the positioning and the terminology here will be important so we got a phosphate group called The Five Prime phosphate attention to the five Prime carbon of the sugar and finally we have up here the nitrogenous base now here's where it gets a little complicated because there are several different nitrogenous bases that could fill this spot in the nucleotide in fact there are five possible bases that could be slotted in up here this is just showing one of them the five nitrogenous bases and again don't memorize their structures but you do need to know other names they are Adine guanine thyine cytosine and uracil um uracil obviously seems like an odd one out just based on its name all the the rest of the ones end in e uracil doesn't and that's an easy way to remember that uracil is actually weird uracil is only used in RNA nucleotides you will not find uracil in in DNA in contrast thyine is only used in DNA you will not find thyine as a building block uh as a nitrogenous base in RNA the other three adenine guanine and cytosine they're found in both you'll find adenine guanine and cytosine in both DNA and RNA uh but these two are our are exclusives thyine is only in DNA uracil is only in RNA now the other thing that you will notice again without memorizing the you know the exact structure here uh is that there are two you know basic categories of these nitrogenous bases um big ones and small ones you know ones that have two rings as part of their structure uh and ones that have one ring as part of their structure there's some terminology here uh which again trust me will be important when we talk about how these things actually work so I'm not just making you memorize fiddly stuff for no reason the big ones Adine and guanine are called purines the smaller ones with only one ring thyine cytosine and uracil are pyrimidines so AG or purines two rings CTU are pyrimidines with one ring just Commit This to Memory this will come up now just like any other polymer we need to l link a bunch of these individual units together into a big long string of things we saw this with polysaccharides we saw this with proteins we're seeing this here uh in DNA and RNA and just like we had a special name for the bond that held together the polymer for those other things we got a special thing here as well it's called a phospho diester bond so in a big string of nucleotides they are linked together by a phosphodiester bond again don't get this mixed up with our other polymers it was the glycosidic bond that did carbohydrates uh sugars it was peptide bond that did proteins and now we have phosphodiester bond that does nucleotides this one's easy enough to remember I think because it's got phospho in the name and this Bond involves the phosphate group of the nucleotide so this isn't just connecting the nucleotides to together it's connecting them at very specific positions so oh yeah we've got our One Prime 2 Prime three prime four Prime five Prime we got it labeled in this figure so yeah here's our five Prime carbon there's the phosphate the five Prime phosphate and we can see where it connects on the next nucleotide it doesn't connect to one doesn't connect to two doesn't connect to four it specifically connects to this thre Prime o group so the phosphodiester bond is is from the five Prime phosphate of one nucleotide to the thre Prime o of the next nucleotide I've got that written here nucleotides are connected by a type of coal Bond called a phosphodiester bond it's the five Prime phosphate of one connected to the thre Prime o of the next and yeah this is just showing three nucleotides uh but yeah DNA and RNA get to be pretty long so you to have many many many many nucleotides all connected by lots and lots of phosphodiester bonds into one big long strand actually I say one big long strand but I think most of us are are familiar with DNA and it's very um unique and cool looking structure that it's not one strand it's two so DNA consists of two strands of nucleotides connected by phosphodiester bonds that have come together to form this double Helix structure so DNA is a double helix formed from two strands of nucleotides what holds this structure together well we know that phosphodiester bonds hold together each individual string but what force is holding these two strings to one another Well if you squint hard you can see a little black dots here if we zoom in we can see it's hydrogen bonds once again hydrogen bonds the weakest of the chemical bonds we talked about but there just so many of them every single pair of nucleotides has several of these things uh so yeah this makes a very stable double helix because of hydrogen bonds uh between these nitrogenous bases uh on the nucleotides and here we see uh an example of how the the pairing up the partnering between nucle nucleotide on one strand and nucleotide on the other strand nucleotide on one strand nucleotide on the other strand is not random it is very specific these two strands do not have the exact same sequence but they do have what is called a complementary sequence these two strands will have nucleotides that partner up in such a way to have the strongest connection possible these uh this these uh are the strongest possible combinations of nucleotides thy me's ideal partner is Adine just if you try to partner thyine up with guanine it just wouldn't have as strong of a connection if you tried to pair thyine up with cytosine or even with another thyine it it wouldn't hold together well the best partner for thyine is Adine the best partner for Adine is thyine the best partner for guanine is cytosine the best partner for cytosine is guanine so here's my illustration here these two strands pair with one another in order to optimize hydrogen bond formation that's why these rules exist these rules uh C to G and a to T I should make this in an extra large font because this is an extra large concept uh these base pairing rules are are very important uh it's how you partner these things up in order to have the strongest hydrogen bonds possible and oh hey using the using this terminology here purines and pyrimidines you'll notice that these always partner up to where you have a purine and a pyrimidine a purine and a pyrimidine if you had two purines two of the big ones they would be to smooshed together uh if you had two of the smaller ones paired against one another they wouldn't be able to reach so these ideal Partnerships a to t t to a g to C C to G these involve a purine paired with a pyrimidine so let's let's walk through an example of this so oh yeah here it is in in much bigger font these are the rules uh C to G A to T and if if you want a dumb way of remembering this to me Capital C and capital G these two letters just they're drawn in a very similar way so in my mind at least it's it's just easy to remember that C and G go together because the two letters just so physically resemble one another and if you remember that c partners with G then the other two obviously partner with one another so what this means is if you have a sequence of DNA here don't memorize this I just made this up CCT t a g c a a if this this was one strand of the DNA double helix knowing these rules you should be able to figure out what the other strand would be so if one strand has C the other strand should have G right across from it the next position should be another G you know C pairs with G the next one should be a t pairs with a then there should be a t then C then G then T then another T then C and yeah repeat this millions of times if you want the authentic experience of building a DNA double helix but yeah this is what I mean the two strands of DNA are not identical in their sequence they are complementary in their sequences according to these rules so this optimal pairing uh results in what are called complementary sequences between these two strands and again this is a great sort of overview figure showing these hydrogen bonds and showing the thyine adenine guanine cine now all this was DNA what about RNA well luckily RNA is just single stranded uh Mo most of the time so we don't have to deal with any of this type of interaction with RNA there's a DNA double helix here uh but RNA most of the time is just single stranded and oh I I also like this figure cuz yeah colorcoded it shows here's that uracil the RNA exclusive nitrogenous base and yeah we see some of this uh pinkish purple only in RNA but not in DNA and there's our thyine blue here um only in DNA none of this blue uh thyine in RNA but yeah DNA is double stranded uh RNA is not so that's the structure what about the function well because of you know this DNA because of this double helix structure DNA is a very stable molecule it has a lot of strength holding it together because of all these interactions in this double helix the function of DNA is unlike the function of anything we've seen in this chapter it's not storing energy or being structural Integrity the job of DNA is to store information so you'll appreciate this more later in the quarter because we will talk about how this stored information actually gets used to do stuff in the cell but for now I'll just say that the job of DNA is like a blueprint it it's the instructions for how the cell is supposed to build proteins and conduct business and respond to things this is the code this is the genetic information this is the blueprint so long-term storage of these important instructions for how to sell RNA in contrast is not quite as stable but its job is often times the same thing a lot of RNA has the same job of being information of being uh a blueprint most RNA functions as as information but it's a shortterm copy of that information so if this is the you know the master blueprint for how to build a house RNA is going to be the photocopy of that blueprint that you take to the construction site and this is going to get dropped in the mud and this is going to get torn and this is going to get scratched up or whatever you crumple this up you throw it away you make a new copy you keep the DNA safe because that's your master copy of all this very important information the RNA is just a short-term copy of that but at the end of the day these are both just instructions these are both just information so most most RNA functions as a short-term copy of of DNA's information it's still an information molecule however it is worth pointing out here and we will see this in action later in the quarter there are actually some rnas that have structural or functional roles there are going to be some rnas that are actually enzymes that make Chemical Reactions happen there are going to be some rnas that support the structures of things that are used to physically build stuff and again we'll we'll see those when when we get to them I just want to note that some rnas are weird but most rnas are a copy of DNA's blueprint information so with that we come to the end of the biological macromolecules chapter uh but not the end of this recorded lecture so with the last few minutes I want to briefly start in on the next chapter chapter four cell structure so we went from atoms to molecules to macromolecules now we're going to talk about organel and and cells so first a a reminder here so yeah I had this in the very first uh recorded lecture here procaryotic cells and eukaryotic cells we're going to we're going to see a lot of this throughout this chapter just to remind you procaryotic cells are the simpler ones uh that don't have a nucleus ukar are the more complicated ones that have all sorts of organel and stuff like that we are ukar uh bacteria are procaryotes so in instead of breaking down you know in a table who has what I actually think it's easy to start out by talking about what we have in common uh we can list a few things that all cells have and when I say all I mean procaryotes and UK carots everyone has the following a plasma membrane so there's there's a whole chapter about the plasma membrane coming up after this one so we'll dig into this more in that chapter but uh this should look familiar it's a lipid bilayer lots of phospholipids here A bunch of other stuff but you know phospholipids and other other things this uh sort of skin of the cell this plasma membrane uh is something that procaryotes have uh yep plasma membrane the sort of thin line around the outside of the cell defining what's in and what's out and yep there's plasma membrane labeled a thin skin around the whole thing uh in a eukaryotic cell as well all cells have a plasma membrane this separates the inside of the cell from the outside and yeah it's it's made of lipids and there are proteins and and cholesterol I guess that's a type of lipid uh it's made of lipids with proteins as well now the other thing that all cells have is a cytoplasm so cytoplasm is to read from the key terms the entire region between the plasma membrane and the nucleus if you have one in other words the cytoplasm is just all the stuff that's inside so yeah here it's just pointing pointing in all this stuff is the cytoplasm it's mostly water it's just the fluid that all these contents are floating around in uh and you know it's not even labeled in this particular figure but the cytoplasm would be in here just this watery space in between all these organel everything has a cytoplasm it just the inside of the cell all cells also have DNA genetic material you know the instructions for how to sell uh in procaryotes the DNA is just floating around in that cytoplasm in ukar that DNA is kept safe within the nucleus organel which we'll get into as we get later into this chapter uh but yeah whether it's floating in the cytoplasm or in a specialized organel all cells have DNA the genetic material the instructions and another thing all cells have ribos s so we see it labeled here in the procaryote it's the tiny little red dots in the UK carote again it's not even labeled here they they they can kind of see them here they're they're even tinier little red dots here uh but the ribosome is something that all cells are going to possess if we want to zoom in on a ribosome and not just see a red dot uh this is a pretty complicated three-dimensional structure uh the job of the ribosome is to to build proteins so it's got two subunits they come together and their job is to be a protein factory to link amino acids together and build proteins um if you're wondering what the ribosome itself is made of again just looks like a cartoony blob right here the ribosome is constructed of protein uh and RNA you know just uh just recently I referenced that there were I can scroll back to that some weird rnas that have structural jobs well uh yeah here we are the there is ribosome RNA that helps build this actual structure that's sort of a weird job for RNA but again ribosomes are things that all cells have they build proteins they've got two subunits that come together in order to do their job ribosomes themselves are made of RNA and protein and there are a bunch of these per cell you know you can see this within the procaryote lots of these ribosomes in each cell again it's not labeled here but you know hundreds and hundreds of these in a ukar Cell as well proteins are really important so you could imagine you want many many many sources of uh of building proteins so these are the things that all cells have procaryote or ukar all cells have a plasma membrane a cytoplasm DNA and ribosomes ukar of course get more complicated than that in addition to all of these things eukaryotic cells also have membranebound organel so structures within the cell that have their own membrane that are kept separate from the cytoplasm and from one another by their own lipid bilayer membrane here's our sort of figures I'll come back to over and over again throughout the rest of this chapter this this is you know typical eukariotic cells this is a pretty generic typical plant this is a pretty generic typical animal uh fungi are also eukariotic cells but for the sake of brevity and uh you know an intro class I won't try to compare and contrast those as well we're mostly just going to compare and contrast plant and animal cells and yeah you could already see all these organel within these cells uh procaryotes um didn't have any of these membrane bound structur structures they had DNA they had ribosomes they had cytoplasm on the inside uh but they didn't have any of these membrane bound organel so yeah like I said I just wanted to briefly get into into this chapter um I'll talk more about that in the next recorded lecture um getting into these membrane organel and membrane bound organel and exactly what their functions are but I'll do that next time so this is the end of recorded lecture 14