all right this is a part two of the cell lecture so we know that the cell has three basic components it has a plasma membrane right it has a cytoplasm and it has a nucleus so we already discussed the the nucleus can be the applies membrane on the first part of this lecture and we know it's consists of a phospholipid bilayer right also proteins get kind of the main function of your plasma membrane is that it acts as a selectively permeable membrane and what that means that it allows only the patches of certain things across the membrane either into the cell or out of the cell all right so the second part of a cell is the cytoplasm all right and cytoplasm by definition is everything inside the cell except the nucleus all right so here's the plasma membrane okay separating the inside of the cell from the out okay the last thing I'm talking about is the nucleus okay but right now what we're talking about is everything else everything else inside the cell except the nucleus so the major things three major things that make up the cytoplasm are the fluid okay so the fluid that's present in side of the cell we call that the cytosol okay in addition to that we also have these other structures and this is very general we'll get very specific okay but these are considered like the organs of the cell we call these the organelles okay and the last one okay a lot of people don't really know about are called inclusions okay and these are temporary structures that are not found in all cell types okay so let's talk about the three starting off with the side is off all right so the cytosol is the jelly-like fluid contains water it contains ions and it contains enzymes okay it makes up half the volume of the cytoplasm and basically what happens here is it suspends to cellular elements okay so this is what the nucleus floats and this is what all the different organelles that we're about to talk about what they float in all right now there's also enzymes present so if things were brought into the cell and it was simply floating in the cytosol well we're gonna probably see some enzymatic okay that didn't occur inside of the song and this is the only side we're gonna talk about the cytosol we're gonna move on next to the organelles all right now the cytoplasm contains about nine different types of organelles now back in the day when I was okay in in in school some of these we actually did not consider organelles okay we always considered organelles when I was in school as membrane-bound structures okay some of these are membrane bound meaning that they have a phospholipid bilayer okay that surrounds them separates the inside of that organelle from the rest of the cytoplasm okay some of these structures are not membrane bound okay meaning that they don't have a phospholipid bilayer okay that separates their insides from the rest of the cytoplasm all right so as we go through these nine different organelles okay well we'll discuss whether or not these are membrane bound organelles or if they're not membrane bound organelles now one important thing to note okay is that we have again different kinds of cells there's 210 distinct kind of cells present in your body okay and the composition of organelles in each of the two head to ten can be different okay so for example you may find some right that have a lot more mitochondria than another cell okay you might see a cell that has okay a lot more peroxisomes than another cell and so forth and so on okay so depending on the function of a cell you're gonna see then the composition of organelles okay correspond then to their function in terms of how much of an organ or possibly not even having a certain organ of depending on their function alright so the first we're gonna we're gonna talk about okay is a ribosome alright and ribosomes right are present okay for what well their function is protein synthesis okay and the fancy name for that is translation so this is the site of translation this is site where your cells make their proteins now ribosomes are made up of two what we call ribosomal subunits all right and these ribosomal subunits are made up of right proteins and of what we call ribosomal RNA okay so it's a mixture of ribosomal RNA and proteins so which is kind of weird right because the function of a ribosome is to make proteins and these ribosomes are made of proteins so it's kind of like the whole chicken and the egg thing right you can't have a chicken without an egg and you can't have an egg without a chicken it's kind of the same thing here okay you can't have proteins without ribosomes and at the same time ribosomes are made up of proteins right so it's kind of a mystery in this case right now ribosomes are made up of two subunits okay a large subunit we call the 60s subunit and a small subunit we call the 40s subunit okay so here's the large subunit this would be the 60s subunit okay and here's the small subunit this would be considered the 40s subunit okay and together okay they make up a functional ribosome individually they do not make okay a ribosome okay it's not until this together do you make a functional ribosome okay and sandwiched in between the large and small subunit okay you guys can see is what we call the messenger RNA all right so the ribosome what it will do it actually will start to move along the message RNA for example let's say we're going from left to right so we've started here okay we end up here and then ultimately we're gonna reach the very end okay and as we read the message RNA okay it tells us what proteins okay or me what amino acids to add in sequence so that our protein gets longer and longer and longer alright so that process of making a growing protein to make it protein we call that translation again alright so there are different types of ribosomes okay that are found in your cells we have what are called free ribosomes and we have what are called attached ribosomes okay free ribosomes and attached ribosomes okay so let's go to our pseudo white board here it's kind of draw very simple setup alright so I'm not gonna draw the whole nucleus well I mean I could all right so let's say here is my nuclear envelope okay okay so this is my nucleus right here all right now out here okay this is then the cytoplasm all right and then here this will be my plasma membrane okay so this then is the outside this is the extra cellular space right so here's my nucleus here's my nuclear envelope here's my cytoplasm here's my plasma membrane here is my extracellular space now where exactly are the ribosomal subunits produced okay well they're produced in a structure inside of the nucleus okay and we call the structure inside the nucleus we call this the nucleolus okay and the nucleolus makes the 60s subunit okay it makes the 40s subunit alright now from there okay then the 60s and the 40s okay they're gonna end up out here right in the cytoplasm okay so here's my large subunit right here is my small subunit right now one thing I want to ask you guys hey is do you or are you familiar with something called the central dogma of molecular biology okay so what is the central dogma of molecular biology well it's this idea okay that information flows from your DNA to your RNA okay to what we call messenger RNA finally at the very end to proteins all right now we know that DNA okay is a nucleic acid RNA is a nucleic acid messenger RNA is a nucleic acid and proteins are proteins okay in terms of macromolecules now the first part here this conversion of DNA to RNA okay we call this transcription okay and to transcribe gate means to copy alright and where does transcription occur within a cell well it occurs within the nucleus of a cell okay we call this transcription the next one here okay from RNA to mRNA right we're gonna call this post-transcriptional modification post transcriptional modification all right and then from mRNA to protein right this is what we call translation okay so we have transcription postural modification translation okay so post transcriptional implication this also occurs within the nucleus now in terms of translation okay where does translation occur well translation occurs okay within the cytoplasm all right so we have transcription which occurs in the nucleus post-transcriptional modification which occurs the nucleus and translation which occurs in the cytoplasm of the cell so if we go back for this drawing here alright so this is my nucleus here okay this is my cytoplasm this is my extracellular space so the first part this conversion of DNA to RNA well that occurs within the nucleus we call this transcription again okay and then post-transcriptional modification okay RNA to messenger RNA also occurs within the nucleus alright so it's the messenger RNA okay we'll draw as let's say this blue line here okay this will leave the nucleus okay and that messenger RNA a will enter the cytoplasm yeah so when these all things come together when the large serving the 60s and the 40s come together okay what are you gonna make okay well you're gonna make then write what's called a free ribosomes so we're gonna now put right we're gonna now put okay the messenger RNA right between the large and the small subunit okay and what's gonna it's gonna do okay is that it's gonna then read the message of RNA okay and it's gonna start making approaches alright so we the process by which there's curves we call it translocation okay the ribosome will translocate along the messenger RNA it's gonna read the messenger RNA and as it reads the measure aren't our RNA it then starts laying down amino acids because what's a protein okay a protein okay is when you take amino acids okay and you join them together alright he make us a chain of amino acids okay and it gets longer and longer and longer asleep the question is well there's 20 different amino acids how do I know what sequence to put the 20 amino acids to make my protein right and that information comes from the messenger RNA so as I read the message RNA okay I an add an amino acid and I read more of the messenger RNA and add another amino acid okay I've read more of the messenger RNA I add another amino acids my protein begins to grow as I add these amino acids together okay and the bond that holds the amino acids together we call these covalent bonds okay these covalent bonds all right hold that the amino acids together okay and hold okay these chains together allow you to now produce your growing protein all right now on the mRNA okay there's a start site okay so there's a site where says basically go okay and on your mRNA there's also a stop site okay telling you where to stop breeding their money and then okay you're done making your protein translations over all right so if we go back to the slide here okay the slice says there's two different types of ribosomes right you have what are called free ribosomes and how you have what are called attached ribosomes okay free and attached so what's the difference okay between the two well free ribosomes are those ribosomes that are simply floating around in the cytosol right so if I draw a cell here right so here's my cell alright here's my nucleus right let me draw a free ribosome here's the 60s here's the 40s and then sandwiched in between again is my messenger RNA so if I'm simply a ribosome reading my mRNA okay floating around in the cytosol okay the fluid again I consider this a free ribosomes here okay so I'm reading my mRNA I'm doing my translation my proteins getting longer it's getting longer it's getting longer and ultimate what happens okay I reached my stop and I released my protein so I start my translation on a free ribosome I end my translation on the free Rob zone when what when the protein I am making okay it's simply going to be released in the desired result okay so let's say we reached the very end right what's gonna what's what's this gonna look like when we then finish translation hey well once I reach the very end of this okay I'm gonna release my mRNA okay my 60s is gonna fall off my 40s is gonna fall off okay and then I release my protein in my cytosol so there is my protein okay my protein is simply floating around in my cytosol well then I'm going to start my translation on free and I'm gonna end my translation on a free okay now what if I want to make more protein well all that has to happen we then go back to the start okay and we do the whole process over again I can make another protein so if the protein I am making is simply going to be released into the cytosol okay I start my translation on our free ribosome I end my translation on a free ribosome okay now in lab okay we talked about okay different types of endoplasmic reticulum okay we talked about what's called right rough ER and we talked about what's called right smooth ER so if a free ribosome is simply a ribosome floating around in the cytosol what do you think and attached ribosome is when attached ribosome is a ribosome that what that Docs itself okay on to the rough ER okay so if I say this is my rough ER here okay what's gonna happen okay if I'm making a protein okay that's not simply gonna be released into the cytosol okay if I'm gonna make a protein okay that is gonna be now one of the three things okay so let's actually write that down okay one okay if the protein I'm making is going to be XO site toast okay meaning that okay it's gonna be released into the cytoplasm or not cytoplasm but um the extracellular space okay well I'm gonna start my translation on a free ribosomes okay we start on a free okay but we're gonna end on an attached ribosomal okay if the protein I'm making is gonna be exocytosed okay - if the protein I'm in making gate is going to be embedded within the plasma membrane okay if the protein on makings can be embedded in the plasma membrane I start my translation on the free I'm gonna end my trip translation on attach ribosome okay so number one is like this okay here's a vesicle okay here are my proteins in this vesicle okay you guys know what extra cytosis is right because we talked about this ready bulk membrane transport okay this will eventually what well it'll fuse with the plasma membrane right you're gonna form a pore okay and when you form a pore well what happens here well you now exocytosed your protein out into the extracellular space we call this exocytosis so if I want my proteins not to be simply floating around the cytosol like this if I want my protein out here outside myself I'm gonna start my translation on a free ribosome okay I'm gonna then dock myself okay onto the surface of the rough ER I'm gonna be an attached ribosome right or number two okay if the protein I'm making simply not going to be released and freely floating the cytosol but the protein I'm making is going to be embedded within the plasma membrane okay like a channel protein for example well then I'm gonna start my translation or free ribosome and then I'm gonna end my translation here on an attached ribosome alright so this would be number one exocytosis this would be to embedded in the plasma membrane or three if the protein I'm making is going to be contained okay in a vesicle okay if the protein I'm making is going to be contained in a vesicle well then I'm gonna start my translation on a free spot a free ribosome I'm gonna end my translation on an attached ribosome okay so what does that mean contained in the vesicle well here is a vesicle okay and inside that are my proteins okay so if that's the case I'm not physically floating around on the side as all like I am there I'm containing the vesicle so if I'm gonna be exercised as a protein if my proteins gonna be embedded in the plasma membrane okay or if the protein I'm making is going to contain in a vesicle you start your translation on our free ribosome but then you finish your translation as an attached ribosome on the surface of the rough ER okay alright so there's two different types of ribosomes okay in your cell either free okay they float in the cytosol they make soluble proteins that simply function inside is off or you have attached ribosomes these ones here make proteins that one are gonna be exercised - okay possibly embedded in the plasma membrane or three okay possibly contained within a vesicle right so ribosomes build all the cell's proteins through a process called what well they make their proteins through a process again called translation right and where does translation occur again well it occurs within the cytoplasm of the cell okay so here okay we can actually see this is an mRNA in blue here's my large subunit here's my saw small so I mean this is where we started we're gonna end here okay so notice that this ribosome is further along the mRNA well therefore it the protein that's growing in orange is a little bit longer okay here this ribosome is at the very beginning of reading the mRNA and look you can see that the protein that we're producing is a little bit shorter okay so this one has just started translation this one's kind of halfway through translation rate that's why the protein is a little bit longer all right now this next slide here kind of shows you the importance of translation okay and why don't we call it translation okay and the reason why we call it translation is if I go back to the to the the thing that it drew about the central dogma microbiology right you're going from mrna to proteins okay an mRNA again is what well messenger RNA in terms of macromolecule is a nucleic acid okay proteins on the other hand in terms of a macro molecule our proteins so we're going from one type of macromolecule a nucleic acid to another type of macromolecule proteins right it's just like if we're gonna go from English okay to Italian right well you need to translate that you got to go from one language to another language okay so we call this process of going from a nucleic acid okay to a protein we call it translation okay so how important is translation well if you don't have translation you don't make proteins and if you don't make proteins you know the cells partment not going to function properly alright this cells probably gonna die okay if the cells die that's the very bottom of our hierarchy that means tissues are gonna kind of fail that means organs okay are gonna fail that means organ systems will fail that means the organism probably is not gonna do very well okay most likely is gonna die all right so what this slide is showing you are certain antibiotics that target the process of translation in bacteria okay so if you were to go to the doctor and the doctor were to prescribe you antibiotics well then what is making sick right now all right well if you're prescribed antibiotics you have a bacterial infection all right so antibiotics are very very specific for bacteria all right so these ones that we're about to talk about okay target specifically the process of translation of bacteria okay and what's the beauty behind them is that they don't interfere with our translation they only interfere with the bacterial trans trans Latian so the first one is chloramphenicol okay and one thing to note if you go look it back at this slide okay bacteria have a large subunit and a small human but their large is a 50s and their small is a 30s okay as opposed to humans we have a 60s large and a 40s small right so there's 50 and 30 we are 60 and 40 okay so if you see here you can see their large subunit is the 50s subunit and their small unit subunit is the 30s subunit so what chloramphenicol chloramphenicol does it binds to the large subunit and inhibits the formation of peptide bonds okay so peptide bonds are those covalent bonds again that link and join the amino acids together alright so if I can't link my amino acid together can you make a growing protein and the answer to that is no okay another one wrecking them all this and we throw myosin okay so what does it read from myosin do it binds to the large subunit and prevents the ribosome from moving and reading the mRNA so if I can't read the mRNA I don't know what the next amino acid is that I should join okay to this growing to this growing protein here all right so again the process translation is very important for the survival of Lorien ISM okay and just the proof of that these bacteria would die okay if you gave them chloramphenicol or we threw myosin right okay the next organelle that we're gonna talk about is endoplasmic reticulum alright and these are examples of membrane bound organelles okay so when I say membrane bound I mean they have a phospholipid bilayer that separates the inside of these organelles from the rest of the cytoplasm right so kind of drawing that out right if I were to draw for example a membrane-bound organelle in here okay inside the cell well you actually would see a phospholipid bilayer okay going all the way around separating the inside of this organelle okay from the outside of this organelle okay there's a membrane that actually separates it and surrounds it from the rest of the cell all right so let's say here is my membrane-bound organelle okay so again it's a phospholipid bilayer right the inside part here okay we call this a cistern oh right and then outside here again this is the cytoplasm on here right so the ER has a cisterna it has this internal compartment that's separated from the rest of the cytoplasm okay so you actually can see here right so here's the inside all right separated from the rest or the outside of there okay here's the inside separated them from the rest here's this is sterno right there now there's two different types of endoplasmic reticulum okay there's a rough ER and there's a smooth ER okay rough ER the reason why it's rough because it has ribosomes okay the first organelle that we just talked about studying extra is external surface okay so what's the name we would give to these ribosomes attached to the external surface right of this rough ER well we call these attached ribosomes again all right if you're gonna take a wild guess okay what function do you think that these rough ER place okay well what it probably does it probably has some roll okay in protein synthesis all right more specifically the function of the rough ER is what well the function of the rough ER is that it produces membrane-bound proteins okay so proteins that are gonna be what proteins that are gonna be exercised host proteins that are gonna be in bed in the plasma membrane proteins that are going to be contained in a vesicle okay have to pass through this rough ER right here and now the smooth ER if you look at this here okay it does not have ribosomes studying taste external surface so if you're gonna take a wild guess okay what does the smooth ER not do what is it not involved in well it probably has no role right in terms of protein synthesis hey there's no ribosomes associated with the smooth ER all right so what's the function of smooth ER well one is lipid metabolism okay the synthesis and the breakdowns of lipids okay to a secondary function for the smooth ER this is where we store calcium okay so calcium is stored within the smooth endoplasmic reticulum all right so go to smooth and we'll go back to rough okay so here you can see right in purple with no ribosomes this would be considered the smooth ER okay so lipid metabolism okay and calcium storage okay this other purple that does have the ribosomes you can see the cisterna here again right the inside and this here is the rough ER alright if we go back to this slide we can actually see here is the cisterna all right here is that phospholipid bilayer okay and studying the external surface of that rough ER here's your large subunit and here is your small subunit okay so here's an attached ribosome finishing its translation as an attached ribosome okay so notice where does that protein that we are translating go what goes into the cisterna of the rough ER right and once inside the cistern of the rough ER it then folds properly okay so it develops a three-dimensional shape that will that'll basically is very crucial for its function okay and then what we do do we just stay in the rough ER as a protein no you butt off okay so very similar to the process of exocytosis you then leave the rough ER contained within a vesicle okay and that vesicle is now floating around in the cytoplasm all right the next organelle is this okay so here's my rough ER here my red ribosomes okay here's this a sternum okay and what we just did we butted off okay here's that vesicle that we just saw okay on this side right here okay so where does this vesicle go well the vesicle goes to our next organelle we call it the Golgi apparatus okay and the Golgi apparatus is another example of a membrane-bound organelle alright so same deal okay it has a phospholipid bilayer separating okay the cisterna of the Golgi apparatus we give the same name it's called this turnip okay from the rest of the cytoplasm all right so the Golgi apparatus we call this and consider this the packaging and the shipping center of ourself okay the packaging and the shipping center of our cell okay consider this kind of the the FedEx the UPS right the Amazon Prime right of our cell now it has three - I believe 10 to 11 disks like structures right where one side of the disk is convex okay so I'm going to draw three disks here I don't want to have to draw ten of them for you okay where one of the side is the convex side okay and one of the side here is the concave side okay well this convex side hey this is the receiving side of your Golgi apparatus okay and the name would give to it we call this the SIS Golgi apparatus okay let's receiving side okay the concave side here okay this is known as the shipping side all right this movie called the trans-golgi apparatus all right so here is my rough ER okay and here's a vesicle hey that just came from my rough ER okay and inside my vesicle here are the proteins that I made ok and what this vesicle will do it'll dock onto then the cysts Golgi apparatus okay so what docks on to then the SIS Golgi apparatus okay and when it docks there we form a pore okay and now these proteins they enter the cisterna okay of my Golgi apparatus okay and then from there they migrate their way down okay to the shipping side and what happens we butt off right we form a vesicle okay and this vesicle now contains the proteins where we're gonna end it okay we're okay where is this vesicle gonna go now hey can someone remind me and tell me okay where this vesicle is gonna go once it leaves the Golgi apparatus well there's three possible destinations you can go right remember we went from a free ribosome to an attached where were the possible destinations well number one we're gonna be exocytosed out of the cell - okay we can possibly be embedded okay within the plasma membrane okay or three okay we can be contained in a vesicle all right so that's what we see actually on this PowerPoint slide so if you look at this this figure here okay here's my receiving side here's my trans Golgi apparatus okay let me see my sis Golgi apparatus I'm receiving the proteins coming from my rough ER okay I then enter the cisterna of my Golgi apparatus where then I butt off then the shipping side I butt off of the trans Golgi apparatus so let's look at pathway one what's happening here okay what just happened to these purple proteins well my proteins have been exocytosed all right that's one possibility - okay here's a vesicle budding off of my trans Golgi apparatus okay and you can see here there's nothing inside the vesicle but there are proteins embedded within the membrane of the vesicle right so when this in cain't fuses with the plasma membrane what happens well the phospholipids of the vesicle will become part of the plasma membrane therefore then what they're for the proteins that are embedded within the vesicle will now be embedded within the plasma membrane so these can be receptors these could be channel proteins right so if now if I'm going to embed okay a protein on to my plasma membrane well this would then be plat way - all right and then pathway three what do we have here well here my blue proteins okay I just have these proteins now embedded within a vesicle or contained in a vesicle all right and there's pathway three so again if I'm gonna be exocytosed if I'm gonna embed my protein within the plasma membrane or if I'm gonna contain my proteins within a vesicle you start your translation on a free ribosome you migrate and then bind yourself onto the surface of the rough ER you become an attached ribosome that's where you finish your translation okay you put your protein into the cisterna of the rough ER okay it folds properly okay we then but off of the rough ER there are my proteins we then dock onto the receiving side the SIS Golgi apparatus and we then get exported out of the shipping side the trans go up a at Pat Golgi apparatus where we can either be exercised we can be embedded within the plasma membrane or our protein can be contained in a vesicle all right all right the next organelle that we're gonna talk about okay is the mitochondria all right and the mitochondria is the power plant of the cell okay more specifically this is where the cell generates its energy a molecule known as adenosine triphosphate or ATP okay and the name of the process between in the mitochondria within that way that we make is we call this cellular respiration alright and we'll get more into that when we talk about okay respiration we talk about the respiratory system when we talk about the digestive system alright now what makes this unique it is a membrane-bound organelle but it doesn't have a single layer of phospholipids it has a double layer of phospholipids alright it has a double membrane okay a double rainbow what does it mean no no rainbow here it's it's a double membrane alright so if we see here there's an outer membrane okay and then there's an inner membrane okay and kind of draw this for you on our our little pseudo whiteboard right here right so when we think about mitochondria okay there's an outer membrane I'll just put om okay and you also have an inner membrane okay and the thing about the inner membrane though it doesn't follow the contours of the outer membrane it actually folds inward okay so I'll put IM here okay and the space that's in between the outer and the inner membrane here okay we call this space we call this the inter membrane space all right now the fact that the intermembrane folds it forms these little finger like projections okay into what we call the matrix k so this middle part here is called the matrix okay and these little finger like extensions that are created by these folds okay we call these little finger like extensions here for example this here or this right here we call these Christy okay so why would I want my inner membrane to fold inward okay why wouldn't I want to see something like this okay let's draw another one here okay so here's my outer membrane okay and then why it doesn't my inner membrane simply just follow the contours of my outer one and I see some that looks like this well the reason is because what why by folding inward by forming this Chris de this one has increased surface area of that inner membrane okay this one here in terms of the surface area of the inner membrane okay it's it's decreased alright so the process of cell respiration requires enzymes and those enzymes guys are embedded within the inner membrane okay so I'm put some and some proteins here embedded in that inner membrane so which one is Manik Andreea are gonna have more of these proteins okay that are going to allow you to produce ATP well the fact that the inner membrane here folds inward okay this one's gonna have now an increased production of energy compared to this one here you don't have as many enzymes in your inner membrane you're gonna have a decreased production of energy of ATP all right right so one kind of cool thing okay is that mitochondria actually have their own DNA it's not linear okay like a chromosome but it's actually circular it's plasma DNA can we call it mitochondrial DNA and that mitochondria DNA comes from your mother okay so if I were to isolate one of your mono conned Rhea and then isolate the mitochondria DNA okay well that mitochondria DNA come from came from your mom okay well then where did your mom get her mitochondria DNA from well she got it from her mom your grandmother on the mother's side yeah well then where did your grandmother on your mother's side okay get her mitochondrial DNA well she got it from her mom your great-grandmother on your mother's side on her mother's side so forth and someone all right so it's the lineage okay of having daughters okay generation after generation after generation okay that allows the passage of this mitochondria DNA from one generation to the next okay all right the next organelle that we're gonna talk about okay are called lysosomes okay and these again are examples of membrane bound organelles so they have a phospholipid bilayer alright there's an inside that's separated from the rest of the cytoplasm okay so these ones are spherical they're shaped like balls basically all right and they contain enzymes all right and these enzymes they are what break things down okay these are what we consider the demolition crew right of yourself okay and the enzymes we call them acid hydrolases all right so if we actually go back to this slide here all right we're gonna call this green structure that's a lysosome okay and the enzymes that are inside that these blue things these are the acid hydrolases right so if I ate something here's a phagosome this is something that I ate this is something I phagocytosed well the enzymes in my lysosomes now digest whatever i phagocytosed here into my cell right so the question is well how did I make a lysosome how did I get these enzymes these proteins contained in a vesicle pathway three okay producing proteins contained in vesicle we just made a lysosome here okay and again the name of the enzyme that allow you for digestion intracellular digestion we call those enzymes inside your lysosome we call them acid hydrolases and again these are proteins alright so here's another picture that let's say we had phagocytosis okay here's my phagosome right here here's my lysosome here my acid hydrolases case when the lysosome fuses with the phagosome well then your digestive enzymes your acid hydrolases break down whatever you just phagocytosed okay alright the next structure we're going to talk about are called peroxisomes alright and these are larger than lysosomes they're also spherical organelles okay they're also membrane bound so here they actually drew it with a phospholipid bilayer okay separating the inside of our practice own from the rest of the cytoplasm okay now these won't contain acid hydrolases their job is not okay intracellular digestion they're not the demolition crews okay what's the job of our proxy zone well the job próximo is detoxification of harmful or toxic substances right so your liver for example okay has lots of peroxisomes we delivered detoxifies things for example your kidneys okay detoxify things so those organs those structures in your body that are involved in detoxification the cells of those organs in those tissues are gonna have lots of proxy somes okay so what do they contain well they contain enzymes is called oxidases and catalysis okay oxidase and catalase okay so one of the things that we want to detoxify our free radicals a and free radicals are just a normal game byproducts of the chemical reactions that occur in your body all right so you reactions your body well some of the byproducts are free radicals okay so what about these free radicals well they're very highly reactive right they like to interact with things why because their outer electron shell contains out unpaired electrons okay and if you remember your chemistry atoms want to pair their electrons okay if that means sharing electrons that means stripping and stealing electrons if that means giving away electrons okay they're very highly reactive right so free radicals it's been theorized these are the ones that take cause aging because the older you are the more reactions you've done in your body okay the more free radicals you've produced in your lifetime well the more damage you can do to your proteins the more damage you can do to your DNA okay the more damage you can do to yourself all right so we got to get rid of these free radicals okay and the peroxisomes one of their jobs is detoxification is to get rid of free radicals right so if we do a little pathway here on the bottom right so let's say here are the free radicals okay very highly reactive we want to get rid of these here all right so through the the first process here we're gonna use what are called oxidases and what oxidase two is going to take the free radicals and it's going to convert okay those free radicals into right water and water but hydrogen peroxide okay now you don't want hydrogen peroxide to accumulate your body so we're gonna take then our second enzyme here okay and our second enzyme here okay is known as catalase okay and what that catalase is gonna do is gonna convert then a that into water and oxygen all right there fart what there for detoxifying our free radicals into something here right that is not toxic so where does this occur again this occurs within organelles called for rocks is somes all right the next organelle okay now we're going to talk about and this is just a review of the endomembrane system the idea of attached ribosome okay going from the rough ER to the golgi and then pathway one two or three right the next organelles that we're gonna talk about are parts of your cytoskeleton okay and these are examples of non membrane bound organelles okay so we're not gonna see a phospholipid bilayer separating the inside of these organelles from the rest of the cytoplasm right so cyto means cell skeleton skeleton okay so these are like the bones and the muscles of yourself okay and to make it very clear okay cells don't have bones cells don't have muscles these are like the bones and the muscles of a cell alright so it provides mechanical support okay that it needs to maintain the shape it also provides the machinery for cells okay to move right in terms of to produce pseudo pods for phagocytosis right to imaginate okay when we when we divide during cell division stuff like that so the cytoskeleton consists of three different protein rods again they're not membrane bound okay starting off with the thinnest in diameter we call those the microtubules okay to me the microfilaments okay the thickest in diameter the microtubules okay and then then the ones in between we call them the intermediate filaments okay so the thickest in diameter the thinnest in diameter and then in between in terms of diameter all right so here are microtubules okay so if I look at from the end okay you can see that the inside is hollow right now to make a microtubule they're made up of proteins called tubulin so if you look very closely each one of these here represents a single protein called tubulin can we take these tubulins okay and then we arrange them okay kind of this in this okay helical type of structure all right and if I were to take my pen stick it here well then it would actually stick out over here okay so they're very hollow structures hey they're very stiff but they're bendable all right now when we talk about microtubules they are dynamic okay meaning that they can get longer they can grow longer or they can get shorter okay so if I wanted to make this microtubule longer all I have to do is just add more tubulin to make this longer right if I wanted to make this microtubules shorter all I would have to do is chop off and subtract tubulin to make this shorter okay now in terms of function right the organelle is attached to and move along the microtubules you can kind of think of the microtubules as a Christmas tree and then hanging off the microtubules kind of like the ornaments would then be the organelles all right now when you talk about multi appendages when you talk about Cecilia for example and when you talk about flagella okay these microtubules here they are found at the core of the cilia there phone at the core of that flagella all right so that's a thickest okay cytoskeleton in the finish would be microfilaments okay okay microfilaments are made up of a protein called actin okay and again okay these ones here are dynamic meaning that microfilms can grow longer or microfilaments can grow shorter okay and how does that happen well either if you want to grow longer just add more act into it if I want to get shouldered shorter well then you just subtract act from it okay now microfilm is involved in a couple things Fran for example right this idea to perform endocytosis or exocytosis right when we manipulate the surface of our cell woman and beaten manipulate the plasma membrane if I want to grow a pseudo pod right well then you now grow these microfilaments towards the plasma membrane causing the plasma membrane to form these okay extensions involved in okay and those cytosis okay what some other functions organelles attach to and also move along the actin filaments and again they are dynamic okay they assemble and they disassemble now in terms of diameter okay in terms of in between are the intermediate filaments okay these ones are not dynamic okay you don't expect intermediate filaments to grow longer and to grow shorter okay they stay the same length all right their job is to do what well their job is to provide tensile strength all right and tensile strength is that pulling forces or is that compressive forces well tension is pulling forces so if you pull and tug on a cell the reason why that Snell didn't just rip in half is because it's cytoskeleton contains intermediate intermediate filaments that then help resist that pulling force preventing the cell from being ripped apart from one another okay all right the next organelle is another example of a non membrane-bound organelle okay and we call these ones centrosomes all right so centrosomes consists of two different parts okay the centrioles which are these structures right here okay that light perpendicular to one another okay here are the essential centrioles enlarged and blown up now surrounding the centrioles you see this yellow cloud okay and this yellow cloud here is called the centrosome matrix okay and the centrosome matrix and the centrioles together they make up what we call the central song alright so the matrix contains proteins that cause these centrioles to grow longer so what exactly are the centrioles well these are the microtubule organizing Center okay and each century all consists of 27 short microtubules arranged in nine groups of three so here's one group of three microtubules second group of three microtubules third fourth fifth six seven eight nine okay so nine groups of three we have 27 short microtubules forming a single central same thing with this central we have 27 short microtubules arranged in nine groups of three okay so the proteins present in the central sub matrix cause then microtubules cause these structures that we talked about in the previous slide to grow from them okay so if you see microtubules where do they come from they're coming from the structure here known as a centrosome all right again found at the core of the flagella of a sperm cell found at the core of these little hairlike structures of skull cilia okay you're going to find microtubules right so if you see cilia if you see a flagella well you expect to see centrosomes present in those cells growing microtubules from the centrioles all right so the cytoplasm consists of three parts one side is all the fluid we only had one slide right organelles there's nine of them we talked about all nine of them some of them were membrane bound some of them are not membrane bound okay and the third thing okay that's rarely mentioned when people talk about cytoplasm everything inside the cell except the nucleus the third thing are called inclusions all right and inclusions are temporary structures meaning that sometimes are there sometimes or not okay that are not present in all cell types okay remember there's two hundred and ten different kinds of cells some cells have these some cells don't have these so they're temporary they're not always there okay and they're not present in all cells so one of them a good example could be pigment right so like melanin for example all right so melanin is a brown black pigment okay you expect for example some of your epithelial cells in your skin the epidermis to have pigment you expect your eyes to have pigment okay you expect your hair cells to have pigments but if I now remove a liver cell you expect melanin to be in your liver no all right so there is a structure that's not present all cell types at the same time it's temporary okay look at your your skin okay in the summer versus okay in the winter okay you're a lot darker in the summer as opposed to the winter why because you get more sun exposure in the summer time so there's an example of a temporary structure not always there okay so melanin pigment would be considered an inclusion okay what else can be food storage for example lipid droplets okay if you're storing lots of fat you're gonna find lodged large lipid job if you're not storing fat you're not gonna see these lipid droplets okay what about your liver cell okay and I'll see your your muscle cells we see glyco zomes gleich assume store what we'll glekas own sort of glucose or glycogen I'm sorry so yeah you have a lot of glycogen stored in your liver when you gonna see these glucose ohms if you now burn that fat glycogen well then you're not gonna see these GEICO's ohms so not all cells have glucose ohms at the same time sometimes are there sometimes they're not they're temporary okay so recapping your cytoplasm again you have what's called the cytosol the fluid you have organelles and you have what are called inclusions temporary structures not found in all cell types alright so the last part of yourself okay is called the nucleus alright so this is the largest structure you find inside of a cell okay it's what we call the control center of the cell why because this is where the DNA is stored okay so if you recall that central dogma of molecular biology okay the information to make your proteins is ultimately stored on your DNA okay so it contains the DNA and it directs the cell's activities case the larger structure inside the cell and if you ever look at the the slides in lab all right you're gonna notice when we stain those those tissues you're not gonna see you know ribosomes you're not gonna see the Golgi apparatus under a microscope you all you aren't gonna see the nucleus though all right because the nucleus is the largest structure you find inside itself okay its diameter five micrometers in diameter all right so here is that nucleus here's a rough ER with ribosomes in red okay so this is not a cell here guys this is actually a transmission TM okay of the nucleus so that's actually the the nuclear envelope okay and there's the nucleolus okay this is the one that makes the 60s in the 40s subunit right here okay all right so what are some structures of the nucleus won't again you have the nuclear envelope okay so this separates the inside of the nucleus from the outside from the cytoplasm okay what did you notice about the nuclear envelope it's also a double membrane okay so there's an outer membrane here and then there's an inner membrane okay in terms of your new Glanville oh now there's some points where the outer membrane and the inner member they actually come and fuse together okay when they fuse they form a pore okay so we call these nuclear pores can you guys name some things for example that may use these nuclear pores okay to exit the nucleus and enter the cytoplasm okay what are some things that will use that okay to then enter the cytoplasm of the cell well if we go back to this all right how did the 60s in the 40s okay get out of the nucleus into the cytoplasm what had to pass okay through nuclear pores okay so there had to be pores here okay that allowed the 60s and the 40s subunit to pass through the nuclear envelope okay what else would use right these nuclear pores well the mRNA okay so the mRNA has to exit okay the nucleus because here's my transcription here's my post-transcriptional modification and there's now my mRNA okay meeting up with the 60 and 40 hey here's my free-rider zone right here okay so this allows things to exit the nucleus kay you're gonna learn the physiology okay we also use those nuclear pore to go from the cytoplasm into the nucleus alright now the next structure of the nucleus that we're gonna talk about okay is what we call the nucleolus okay which is right here alright it's a little nucleus it's in the center of the nucleus sums some nuclei have just one some have two all right and the function of the new clothes well this is the site of the production of the ride was almost subunits K so production of the 60s seventeen it the large subunit production of the 40s subunit the small subunit okay now in addition to those two things okay the nucleus also has the genetic material okay the nucleus also contains what we know as chromatin okay so what is chromatin chromatin okay is a combination of two things chromatin is a combination of DNA hey and what are known as histones all right so chromatin okay consists of two things okay DNA I have DNA simply as this black line here okay and histones and histones I'll just have as this green ball here so when people describe chromatin they describe chromatin as beads on a shrink okay beads on a string my pen just died so I'm using my mouse to do this sorry about this beats on a string all right so if I combine the two now right so here are my histone proteins and use a bigger tip okay so here are my histones and I'm gonna take my DNA and I'm gonna wrap them then around my histone proteins okay so we can look like looks like these beads on a string well I now have my DNA and my histones together I have what we know as chromatin okay so this section here guys okay where I have DNA and histones together okay this here is known as a nucleosome okay so the region here that is just DNA and no histones what we call this free DNA or we also known call this link or DNA I'll just call it free DNA right here okay it's also known as linker it's very hard to write for the mouse alright so when we think about histones it looks like beads on a string can be a chromatin it looks like beads on a string okay and it consists of nucleosomes free DNA nucleosomes free DNA nucleosomes so forth and so on all right okay so what you see here okay again is a transmission e/m right electron microscopic image of the nucleus that's the nuclear envelope okay here's the nucleolus is where the 60s and 40s are produced and you can guys can see this lighter stuff here and this darker stuff well all this here represents chromatin okay that's chromatin right there all right so let's talk about the DNA part of chromatin okay let's talk about okay the genetic material so DNA consists of two strands okay is what we call double-stranded molecule it's it's double-stranded molecule so here is for example one strand okay and then here is a second strand now the two strands are what we call complementary to one another okay and what exactly does that mean right well DNA consists okay of what we call nucleotides right there's a and G we call those the purines and then there's C and T we call those the pyramidal okay so a engineer the purines C and T are the parameters all right and kind of the easy way to remember that is to think about a perimeter yawns a lot like pyramid right so I think of a pyramid that looks like this okay in the top of the pyramid is sharp and it can cut you okay so that means C's and T's are like this pyramid right here okay so season T's are the perimeters that means then whatever's left over the a and the G then must be the purines then all right now the way they pair up okay is that a x' pair with t's okay so this is an a adenine this is T this is timing they pair up okay jeez and C's pair up and vice versa C's pair with cheese okay so these are complementary to one another okay so when we say they're complementary they form base pairs with each other they form hydrogen bonds okay so between c's and g's we form one two three hydrogen bonds between a's and t's we form two hydrogen bonds okay so if I go back to this slide here okay where we said that the two strands are complementary to one another you can see that aids parities sees pair with juice okay aids parities sees pair of G's so if I know the sequence of one of the two DNA strands okay can you predict then the sequence of the complement air strand is the question alright so if one of my friends for example was that say T okay a G C alright can you predict then the sequence of the complementary strand alright well yeah you can right so if that's a C well then complementary to that would be G well that's a G complementary to that would be a see if that's an a well that would be a T well that's a T well then that would be an A okay so the two strands are complementary to one another and what's what's holding them together again are these hydrogen bonds between A's and TS are two hydrogen bonds okay so two hydrogen bonds between GS and C's three hydrogen bonds holding them together alright now kind of on site note here guys another thing about the two DNA strands is that they are what we call anti parallel to one another alright meaning that there's directionality to the strands okay so every DNA strand has what's called a 5 prime end and a 3 prime end okay so we say anti parallel well that means then the complementary strand is op running the opposite direction so this is running 5 prime to 3 prime well then the complementary strand is running in the opposite direction okay so that's the 5 3 prime this is Phi Prime okay well if that's Phi prime well then this is the 3 prime end of this strand okay so we say that the two strands are what we call anti parallel to one another all right okay now dad more to your plate here okay DNA doesn't simply run the strands don't run just parallel like this right here okay okay when we think of DNA it is actually a helical molecule so instead of being straight up and down like this if we were to twist one of the two ends okay well now you're rope ladder would look like this okay and this is a a clear representation okay of what DNA actually looks like it is a helical molecule that we see right here okay all right so here is my DNA and we just talked about it okay so to schranz antiparallel a helical okay we would call this just simply naked DNA okay there's nothing associated here all right okay and then we have here okay these are the proteins these are the histones okay so DNA and histones we form what's called beads on a string okay well this is chromatin right so again the histones with the end we call that a nucleosome right there now from make a DNA to chromatin we can actually can pack this even more okay you form this right here this is what we call super coiled the DNA okay and the best way I can explain super coiled DNA to you is if you know if you had a landline and he had a telephone right you had a corded telephone not a cordless one but a corded one okay and you pick up the receiver and you hang it up and you pick it up and you hang it up and you pick it up again and this time sometimes you you turn your back because you're cooking something or you turn your back because okay you want to watch the TV okay over time okay that telephone cord is gonna wrap itself basically right it's gonna be to the point where you can't pull it very far because it's is twisted and turn so much okay that's more that's kind of like supercoiling your DNA okay so we're gonna take DNA it's ready compacted in the form of chromatin okay and we're gonna actually coil it even more all right and the highest order level packing is all the way down here we call this a chromosome okay so the only time you see chromosomes is when a cell is dividing okay this is the highest order and level packing you never see this unless the cell is actually dividing so things like mitosis for example things like meiosis okay you're gonna see chromosomes right the highest order and level packing now back to chromatin right here okay beads on a string there's different forms of chromatin you can have a condensed form we call this heterochromatin right or you can have an extended form of chromatin we call this you chromatin all right you chromatin is spelled EU chromatin all right so you can have heterochromatin which is the condensed form or you can have the extended form of chromatin called you chromatin okay all right so on the bottom of this okay we see a question to you guys okay how many chromosomes are there in a typical human cell alright so how many do you get from mom had me how many the chromosomes you get from your dad well you have 46 total chromosomes right so when that sperm cell that had 23 chromosomes fertilize that egg that had 23 chromosomes well then the zygote okay comes up with 46 chromosomes okay so here on this next slide we see what's called a karyotype okay and a karyotype is a pictorial representation okay of the total number of chromosomes within and within an organism alright so here we see right the 46 total chromosomes here so a couple of turn ology here right here our chromosome one okay how many copies of chromosome one do you have you have to write how many copies of chromosome two do you have well you have to have me copies of chromosome 13 do you have well no - and the copies of chromosome 21 do you have - okay so why is that why do I have two copies of every chromosome here because you got one from mom and you got one from dad for every single one of these chromosomes you got one from mom you got one from dad this is the one that was in the egg this is the one that was in the sperm this is the one that was in the egg this is the one that was in the sperm this is the one that was in the egg this is one that was inspir so 23 of your chromosomes came from your mom 23 of your chromosomes came from your dad for a total of 46 right so some terminology here all right what is the name okay we give to these matching chromosome ones here all right so if I have a chromosome okay one okay I'm gonna shade this one in okay and let's say I got this one okay chromosome number one from your dad from dad okay and I have this other matching chromosome one okay I'm not gonna shade it in okay and this is the chromosome one that you got from mom okay what do we call these matching chromosome what's what's the term we use okay to describe matching chromosome ones well we call these homologous chromosomes homo means same right so homologous sorry guys I can't write with the mouse chromosomes put a period there alright so one question I might ask you to go to the actual slide okay our homologous chromosomes identical to one another is this chromosome one that you got from your mom identical to this chromosome one that you got from your dad yes or no well the answer is no right okay they're gonna have the same genes on them okay and let's say there's a gene from my color well there's one on chromosome one there's a gene of Fri color and - one with someone but the thing is okay is it possible that mom has a different form of that gene let's say she has blue eyes and your dad has brown eyes so yes you still have the same gene on it for eye color but the form of that gene can be different from one another okay and the best way I can make this so that it may it makes sense right is this right homologous chromosomes are not identical but they are similar to one another okay they're not identical but they are similar right because they're both chromosome ones they're gonna have the same kind of genes on them but the kind that the form of each team though could be different you know the I gene is here the I gene is here but this is blue that's brown okay the hair color gene is here and the hair color genes here but this is for okay brown hair and this is for blonde hair all right so the same kind of genes are on them but the forms of each gene could be different okay and the best way you can make a make make us understand it is this right is a shoe on your left foot okay identical to the shoe on your right foot like a pair of shoes right okay are they identical the answer is no right one is a left shoe one is a right shoe if they were identical well you can just arbitrarily pick up any shoe put it on either foot it would be perfectly fine right they're not identical a pair of shoes are not identical but are a pair of shoes similar to one another yeah okay they're both they're both made by the same company they both have the same color away unless you're getting all like fancy dip wearing different colorways right so they're very similar to one another but you know they're not identical that's the same thing here this homologous pair these homologous chromosomes are very similar to one another but they're not identical to one another okay very important you know that so how many pairs you have you have 23 pairs all right so this is a karyotype of what is the care type of a male or this is the karyotype of a female look very closely okay how can I tell if this is a male or female well look at the 23rd pair here okay this here are the sex chromosomes okay and I see an X chromosome and I see an X chromosome I see two x's well we know that this is a female then because females are xx males are X Y and the Y chromosome was very small okay you would see a very tiny chromosome if it was the Y chromosome all right so this last pair this 23rd pair tells us whether or not is a male or female okay so the name we give to all the other chromosomes so this is that these are the sex chromosomes XX or XY if it was a male all these other ones chromosome 1 2 3 4 already chromosome 22 we call these ones the autosomes okay so we have one pair of sex chromosomes okay so if I'm talking X x 4 XY these would be your sex chromosomes depending if you were a female or if you were a male okay but the remaining chromosomes okay chromosome 1 to 22 we call those ones the auto somes okay that's a uto som es okay so you have one pair of sex chromosomes okay you have 22 pairs right of autosomes okay so one pair of sex okay 22 pairs of autosomes okay total of 23 pairs alright so here we kind of review the central dogma microbiology you guys can see here's our DNA which goes there's a skip that's not gel in here to RNA to messenger RNA we use the nuclear pores we enter the cytoplasm here's our 60s subunit here's our 40s subunit here is our growing protein consisting of amino acids here okay so the central dogma home like a biology alright so this next slide here just kind of shows a review of different organelles alright this may be a little different from the one that's present actually in your slides but it pretty much shows the same thing okay in terms of all the different organelles that we talked about all right so we'll stop there okay and what we'll pick this next part of the packet on part three of this lecture and hopefully by then my pen works okay all right so I have a good day guys and I will see you on the next lecture okay bye