Transcript for:
Understanding Cell Organelles and Their Roles

all right in the next segment I want to talk more about the function of the you know the different types of organells within cells and their function all right and as you can see here I have bulleted out the major um internal parts of a cell that I want to discuss now the first one the cyol think of the you know remember we mentioned CYO plasm and they when we started talking about the three major parts of a cell we said that cells have a plasma membrane we said that cells have organells in a cytoplasm and then we said that the nucleus is uh you know a big important entity within the cell as well all right and what the cyol is think of the cyol as basically the water and the non-living components that you find within the cell okay so B basically you know if you take a look inside the cell you know that there are all these working parts you know there may be a nucleus some Er goldi ribosomes okay and then there's a lot of water soak you know within the cell as well okay that would be the cyol of the cell all right then any you know any proteins or molecules or ions or whatever that would be found within here as well okay so the fluid within the cell and the non-living components that are dissolved with then the fluid uh make up the cyol all right and then the nucleus of the cell that is basically the control center of the cell I'm going to talk more in depth about these individually in a little bit all right then you've got what are called the endoplasmic reticulum the rough endoplasmic reticulum and the smooth endoplasmic reticulum now the endoplasmic reticulums are often abbreviated eer okay and when we're talking about the rough endoplasmic reticulum we would abbreviate that as the [Applause] r and the smooth endoplasmic reticulum would be the s r okay so keep that in mind as we're going to our discussion and I don't feel the need to write all these out when we can just abbreviate these terms all right and then we've got something called a GGI complex or it's often called the GGI apparatus as well either way I don't care how you use it just as long as you um use it in the correct context and uh um and I typically call it the GGI complex so and we'll talk more about the function of the GGI complex and ribosomes ribosomes are very important little structures within the cell these are basically the sites for protein synthesis we've already started talking about mitochondria a little bit and we said that mitochondria uh within the cell is where eight where the bulk of ATP is generated remember the the the the fuel for so the cell can perform the bulk of work and then cells also contain these little structures these little pouches called lomes and peroxisomes that are basically used to think of it as keeping the inner workings of the cell clean I'll talk a little more about those again in a bit and then cells also have a skeleton as well have a framework um that give them a specific shape all right so on that note let's kind of move on and so we'll start with by taking a look at this General represent presentation of a cell and talk about the individual parts that we see here within the cell so as you take a look at this image um what you'll notice you know there are various parts within here now bear in mind you know as I keep mentioning you know that these cells are found in very watery environments okay you know the cyol of the cell there's a lot of water inside the cell you know the extra cellular fluid um you know lots of water around the outside of the cell Okay so as a result you know the this water is constantly shifting and moving around and as a result these organel are always constantly shifting and moving around as well the nucleus isn't always smack dab in the center of the cell okay like you always see it drawn in the books the nucleus shifts around a little bit this ER is going to shift around a little bit okay so bear in mind that these cells are very Dynamic structures because remember the fluid mosaic model that we started to mention when we were talking about the plasma membrane you know the fluidity of the cell membrane into the cell itself okay the cells are very flexible yet tough durable little structures all right so now as we take a look at this cell here we can see a few different parts so first let's talk let's talk a little bit about the cytoskeleton okay the cytoskeleton okay or the framework of the cell all right so as you take a look here you know if you look inside the cytoplasm here you can see what looks like a bunch of filaments okay see all these you know stringy looking objects within the cell okay those filaments are are pro are structural proteins that that form the framework of the cell because when the in the next chapter when we start covering histology you know one of the very important Concepts you have to learn about histology when it comes to understanding what tissues look like if you want to identify tissu isues you identify tissues by looking at the shape of the cells that are within the tissues and there's other things you look at as well but that's one of the big ones okay and you know depending on the proteins and the arrangements of these proteins within the cytoskeleton will give cells certain Frameworks and shapes as well all right and there there are various proteins you know there are microtubules okay there's actin sometimes you'll see some masin okay and other and other proteins that um that that form a framework within the cell and then what they well these what these proteins tend to do is they tend to um they tend to form kind of a scaffolding like Network around each other and like I said that as you arrange these in in a specific fashion that will give the the cell it shape and realistically that's I mean that's all the you know I mean that's all the cytoskeleton does it's like our skeleton it just gives us a framework and a shape now you'll notice here as we kind of take a look within the cell as well that there is this spindle like structure found you know in here as well now that's comes as a result of the FR of the cytoskeleton as well this spindle apparatus or what we're called the cental this is very important for the next topic I'm going to be covering um mitosis okay you know cellular re know nucle division so nuclear division s the reproduction however you want to call it okay because these spindle fibers here you'll notice that as as you take a look at this spindle structure here there's a lot of proteins projecting off of there all right and what happens basically when we want to divide a cell what happens are these spindles migrate to each pole of the cell and then what they do is they pull on chromosomes with the genetic material and these spindles kind of Branch out grab onto the chromosomes and then they pull them to towards each pole all right and then the cells going to split in two and then form two you know ident genetically identical daughter cells all right so these are very important we're going to come back to these when we talk about mitosis and cell and uh nuclear cell division in a little while all right but that's all those are like I said those are derivatives of the cytoskeleton as well all right so the cyto skeleton forming framework and also plays a little bit of a role in mitosis or cell division that's all you really need to know about the that's all you really need to know about the cytoskeleton framework of the cell all right now as we kind of continue and take a look at some of these other structures um you know I mentioned that there are what are called lysosomes and peroxisomes okay as you can see these kind of sacklike structures here within the cell all right um what these are basically what these are if we you know lysosome or a peroxisome okay lyss in medical terminology means think of that as to break okay think of lice as to break okay so if we're talking about lysosomes what these are these are little pouches or packets that contain enzymes okay digestive enzymes all right so basically what these lomes do then is these enzymes break apart materials you know organic materials so for example remember we talked a little bit about fyto very not even a little bit it was very brief about phagocytosis you know we said that there are phagocytes that you know that they they wander by these foreign materials and they create these invaginations in their cell membranes okay and then they create these little these little sacks called fomes and then what happens okay so then we let's say this let's say this Green Dot represents a bacteria okay and then what happens once this once this fosite fagos tizes or eats this bacteria then what's going to happen is a lome is going to fuse with this all right it's going to fuse with this and then these enzymes that are inside of here are going to are gonna works are going to be basically dumped out or released into the fagoo and excuse me and then what and then that's how this fagite is going to digest this bacterium or whatever foreign material that it that it consumes all right so lomes are basically used for digestion purposes and we need them for other for other things as well I mean it's more than just phagocytes utilize those lomes I mean for example if we have a mitochondrian or this ER or GOI or whatever it is we're talking about out here um you know if we have you know organel get worn out okay organel like anything else organic are going to fall apart over time all right and but we can replace these uh these old parts of the cell these organel of the cell and but you know just like a like a part in your car for example if your alternator goes bad you have to take the old bad alternator out before you place a new one in there okay so we have to get rid of the bad part all the bad fragments and the useless part before we can actually you know build a new one and replace it all right and that's what lomes are going to do is they're going to break down that old worn out organel as well all right so that's all they do and they're they also play a role in something called um Auto fasy or we can think of another term for it as apotosis all right because there there are certain situations when cells just get rid of themselves cells you know a lot of people like to call it cell suicide okay and basically there are there are certain situations when this does happen for example if a cell takes on a lot of damage uh for example if we develop a cancer cell um or a bad defective cell and a you know a natural killer cell or or or a cytotoxic tea cell you know cells of your immune system you know what they'll do is they'll basically fuse with this bad cell they'll dump a bunch of digestive enzymes or called granzymes inside the cell and that what'll happen is these enzymes will break this apart from the inside out okay and then what'll happen is let's say this is a tumor cell this cell will be so damaged on the inside it'll be so damaged Beyond repair the only option it'll have is to kill itself okay and then the lomes that are within the cell are going to start to break open release the enzymes all over the place within the cell and then that will break apart the organel and be basically be the demise of the cell itself all right so that's basically what lomes are are there for fogos sites use them to digest uh whatever it is they consume you know we use them to replace worn out organel and they're also involved in apotosis and what's interesting I mentioned the the apotosis as well is that there are C what's weird about it is there are certain situations where we don't exactly know why it happens okay for some reason some cells just get rid of themselves and we don't know exactly why all right but you know but apotosis is a if you go more in depth with it and study it it's a very interesting phenomenon that occurs within cells it's a very systematic way that cells have of getting rid of themselves all right and peroxisomes do essentially the same thing except for they use they use peroxides okay um you know like hydrogen peroxides and so on to break down more inorganic type um materials that could get in that could get into cells as well all right um so that's basically so that's basically what peroxisomes do they take care of the inorganic material lomes take care of the organic material all right so basically in a nutshell these two are oops these two are keeping the cell clean all right so lomes and peroxisomes all right so those are kind of the uh the oddballs the cytoskeleton lomes and peroxisomes now let's talk about the major really working parts of the cell all right so there's a few there's a few different parts on here first we have a nucleus then we've got some mitochondria okay and then you can see there these kind of invaginated folds here this one is the rer the rough endoplasmic reticulum this here is the smooth endoplasm reticulum all right and then this is the GOI complex all right and then we mentioned you know the spindles and the fibers the parts of the cytoskeleton now what these are these little these little dots you see all over the place out in the cytoplasm these are ribosomes okay those are ribosomes and then we we've got some it could be peroxisomes or lomes all right and then everything else you see is the cyol the fluid and the non-living components that all this that all these working parts are kind of bathing in within the cell all right so let's talk about let's talk about all these various parts of the cell and how they work now what's fascinating and interesting about these different organel is that they're almost like assembly line okay so basically you know we've met we've been saying this whole time that cells are the functional units of life okay the smallest working parts that can give us life you know because when I mentioned my hierarchy of complexion you know I said a mitochondrian alone can't is not good enough to give some you know to sustain life a nucleus is not good enough alone to to give us life and an ER and so on but when we take all these individual parts and we put them together then we can form a living entity I.E the cell all right and then and then these diverse cells then give us function and give us life all right and like I said you know as I mentioned before you know keep in mind as I'm talking about this that no cell in the body is going to look exactly like this okay because cells are going to have I mean almost all cells are going to have a nucleus but they're going to have varying amounts of this endoplasm of this rough endoplasmic icum of the G you know mitochondria and so on okay so that's so that's where you see the diversity in the function of cells all right is within you know when you when you look at these under a microscope or images of a of cells under a scanning electron microscope and you see how many different you know the variety of different parts and how many of the parts there are that will that will dictate a lot of the the function of the cell so understanding these organel can tell you a lot about the jobs that these cells play so as you're going through and learning about& and you are you know studying the cellular composition of certain tissues you know understanding the basic functions of these organel are going to tell you a lot about the jobs that those tissues play all right so on that note let's start talking about the different organ you know these organel and how they work all right first let's put our focus on the nucleus okay let's put our focus on the nucleus erase all that do the easy way I always miss something all right so first we'll talk about the nucleus okay the nucleus is the largest organel that you find within the cell all right and the nucleus is you know not only the largest organel it's probably the most important organel as well all right now within the nucleus um you know you're going to find DNA okay that's where we find the DNA of a cell and you know as we're going to talk about later on DNA is basically what makes us who we are okay DNA is what we use to synthesize proteins it's a code all right so within the nucleus itself is is where you find that now it's important that we store DNA inside the nucleus because DNA is a fragile molecule all right and damage to DNA could cause you know could could lead to or cause mutations in a cell and that's really going to that that could vary well mutations almost always negatively affect cells okay and I mean for example if we damage DNA enough enough in certain cells that could cause you know them to make bad copies of themselves and form in cancer cells all right and so on now you'll notice when you take a look at this DNA that it has its own little parts to it as well if you look at this Dark Inner portion that's the nucleolus okay that's the nucleolus of the of the of the nucleus and then you can see that it has an inner and an outer membrane all right and this outer membrane is what we call the nuclear envelope okay it's the nuclear envelope all right and then what you'll notice excuse me what you'll notice next are that there are these pores okay that we call nuclear pores all right those nuclear pores are very important as well all right so the nucleus has a couple different parts to it as I just mentioned and these parts do serve various purposes um excuse me so basically so basically what we're looking at here are when we look at these different parts now one thing you need to keep in mind about this is that DNA does not escape the nucleus okay DNA does not escape the nucleus all right but all these various part almost all these parts out here in the cell are used for synthesizing and making proteins all right now I just mentioned earlier that DNA is the code for making protein so obviously if DNA cannot leave the cell there has to be some other way of doing this all right and basically we use um what's called RNA more specifically messenger RNA you know it's it's a it's a message template that's formed from DNA and that that RNA travels out these nuclear pores to the protein making Machinery of the cell all right now you have to bear in mind that's all cells do that's the number one job and function of a cell is to crank out and synthesize various proteins because these various proteins are what give us life you know the proteins that make up the the structural composition of your the cartilage in your knee the proteins that you know the proteins that act as enzymes that that perform chemical reactions within the cell proteins that can be used within the plasma membrane as receptors or Gates or you know proteins that code for eye color okay all those proteins that drive life are synthesized from DNA okay and um and all this here you see within the cell that's where you find all the chromatin or kind of the the tightly packed stored DNA within the nucleus and then this nucleolus this very very dark area that's basically where you find um DNA that's used to make uh what's called R RNA or so you know something that's very important you know in in producing ribosomes and making proteins all right so that's basically what we use the nucleus for we store DNA in there all right we store the message to make protein all right that message then is transferred out of the nucleus through these pores out to the protein making Machinery of the cell all right I'm gonna talk much more about this in depth later on when I talk about transcription and translation and how we you know and how and and cellular Division and so on but that's really all the nucleus is that's why we call it the command center of the cell because you know that's where DNA is stored and DNA basically directs all the activity of the cell all the protein making activity of the cell because that's when you look at this when you look at this image that's the bulk of I mean that's the bulk of the job of a cell making proteins all right so then next when we take a look at this let's take a look at the rough endoplasmic reticulum next okay and the reason why we call it rough is because you'll notice that there these that looks very granular in appearance okay and you know if you if you at this under under an electron microscope it is going to look very rough in appearance and what these little specs are those are ribosomes okay and as I mentioned before ribosomes are the sites of protein synthesis so you can guess then what the rough endoplasmic reticulums main job is okay this is where we make proteins okay more specifically proteins that are to be exported okay so typically proteins that are synthesized in the rough endoplasmic reticulum are exported out of the cell all right so now if we want to look at the at the design of the endoplasmic reticulum what you're looking at here is an extension of the nuclear envelope okay so the rough ER is essentially just it's an out pouching or outgrowth of the nuclear envelope into the cell and then you'll notice that the that the rough endal plasma culum has a lot of folds um you know it's a it's a very folded type organ all right and basically these you know as it folds like this this basically allows us to conserve and save space all right so we can so you notice we can store a lot of er within the cell all right so that's all you really need to think about this so for example let's let's apply this rough endoplasmic reticulum let's say you're talking about a B cell all right B cells are cells that we use to prod antibodies okay you guys know that antibodies are proteins that we use to combat you know infections and illnesses all right so what happens so let's say you've got a viral infection you've got a flu all right this if this B cell comes in contact with this virus then what it's going to do is it's going to it's going to start to divide but it's going to form these very big looking cells called plasma cells all right and these plasma cells all they are they're basically just nucleus and almost all rough endoplasmic reticulum okay they're almost all nucleus in rough endoplasmic reticulum all right and this rough endoplasmic reticulum like I said is its main job is for producing proteins that are to be exported out of the cell all right so this is where these antibodies come from that's the main job of this so then this plasma cell is just it's just going to sit there and synthesize antibodies at a very rapid rate that are going to be excreted into your body fluid so you can help fight um the infection that's you know that's infecting you sorry I can't think of a better way to put that okay so that's the rough endoplasmic reticulum all right so the so the the DNA in the nucleus then is shuttled out to these ribosomes on the ru ER and these proteins then what's going to happen as we start to synthesize these proteins within the rough endoplasmic reticulum they're going to you know they're going to be enveloped within these sacks all right they're going to be enveloped within these sacks and eventually what's going to happen is they're going to come in contact with this next structure called the GGI complex okay the GGI complex okay so Bas so just like the rough endoplasmic reticulum all right proteins that pass through the GGI complex are going to be exported from the cell all right now the Gogi complex you'll notice is it it looks very similar to the rough ER except for the fact that it doesn't look granular in appearance okay there are no ribosomes on it so the GOI complex is not is not responsible for making proteins but it can modify proteins you know this is where proteins become conjugated in cells you know where we'll tack on a carbohydrate or a lipid okay this is where a lot of carbohydrates in general are are are synthesized you know remember we mentioned that the plasma membrane is made out of phospholipids all right you know a lot of you know the phospholipids are you know are are designed here as well so basically what's going to happen then as we develop these proteins in the ru ER and then they'll migrate and pass through the GOI complex then what'll happen is they'll be in these vesicles these stor these vesicles and remember we talked about exocytosis in the previous lecture and these vesicles then are going to fuse with the plasma membrane as you can see going on here and then once they fuse with the plasma membrane then a couple of things may happen you know if this is a you know this is a bunch of protein to be you know like a neurotransmitter or a hormone or a chemical message of sorts then they are going to they're just going to be released out of the cell itself sometimes these proteins or molecules you know like the phospholipids are going to fuse with the cell membrane and then become a part of the of the plasma membrane okay but they're still being exported out of the cell but they're on the outside of the cell and serving a function to the cell itself all right so you notice that we have this assembly line here that is that we use to synthesize proteins because like I said that's the main job of a cell you know you know putting together proteins to either be exported or to be used by the cell itself this eraser is not working all right and as I mentioned before or in in the previous talk when I was talking about osmosis and tonicity what the heck okay when I was talking about osmosis and tonicity all right remember that the that these that these parts of the cell are you know in order for all this to happen they need to be a certain distance from one another all right so if we become hypertonic and the cells and basically water escapes the cell via osmosis all these parts are going to get scrunched together and it's not going to work all right it's not going to work properly and vice versa if we are if our body fluids become hypotonic and the cell SW you know if water goes into the cell and the cell swells up okay all these working parts are now going to be pushed farther away from one another and again like an assembly line in a factory it's not going to work properly there's a reason why when you look at assembly lines and factories there's a certain distance between where they make all the parts okay because if you're too close together you're going to just be well you're not going to be able to work properly while you're banging into each other and if you're too far away it's going to take too long to make the parts so the spacing is important as well and that's why maintaining water balance is important okay so the nucleus is where we store DNA all right and remember DNA is a code to make proteins all right so then we use that code and that code goes out to the rough endoplasmic reticulum and the ribosomes are the specific sites all right where proteins are synthes synz and then once we synthesize these these proteins then they and then basically you know the these with these folds of the ER they form these sacs and then the proteins are stored within them and then they'll migrate to the GGI then like I said the GGI is GNA modify the proteins it could make like I said conjugate whatever it may be and then and then these and then as as these vesicles pass through the GGI then they're going to fuse with the cell membrane and I said either be exported or you know completely out of the cell or be exported to the to the plasma membrane itself all right so that's the nucleus the Ruff ER and the GGI okay now you'll notice that again there are some ribosomes out here and there are there there are free we would call those free ribosomes okay and just like the ribosomes attached that are that are associated with the rough endoplasmic reticulum those are also sites for protein synthesis but typically when we synthesize proteins on free ribosomes these are proteins that are to be used within the cell okay you know like replacing enzymes that drive certain metabolic functions or structural proteins like the cytoskeleton and so on okay so that's the difference between the ribosomes that are bound to the Ruff ER and the free ribosomes of the cell okay protein synthesized and free ribosomes are used within the cell protein synthesized in the rough ER are exported from the cell all right so next let's talk a little bit about the mitochondria all right now the mitochondria are very important because that's where as I mentioned before that's where the energy comes from to drive all of this activity within the cell all right and basically you know you know remember we we've already started talking a little bit about ATP I'm going to talk more about ATP when I talk about metabolism later on okay but basically this is where the bulk of ATP is synthesized we can make ATP within the cyol of the cell through a process called anerobic respiration all right but that's not a very we don't make a lot of ATP as a result of that it's not a very effective mechanism to make ATP all right so basically most of the ATP is produced within the mitochondrian through a process called aerobic respiration we say aerobic okay you should basically think we're using oxygen okay we're burning oxygen if I say anerobic okay I'm saying without oxygen all right and like I said as you'll learn as I as I talk more specifically about the steps of this in another lecture uh that making the making ATP with the use of oxygen is a lot more efficient and we yield a lot more ATP as a result okay so you know as I you know remember before when I was talking about proteins in Chapter 2 the average protein is about 25,000 to 50,000 amino acids in composition okay that's a I mean that's a lot of molecules proteins are big bulky molecules they're much larger than um they're much larger than carbs and fats and water and many other ions and solutes and particles that you find within the within the body itself all right so so we're making big molecules that takes a lot of energy to make these big molecules all right hence the need for these mitochondrian all right I mean that's the that's mainly what they're fueling is protein synthesis all right and there are certain cells of the body that have more mitochondrian I mean typically I mean typically this is easy to think about the more active the cell the more met abolic active the cell the more mitochondrian are typically going to be within that cell so when you start to think about what are the more active tissues of the body well I mean an easy one that pops into the mind is muscle tissue okay muscle tissue is very metabolically active we're constantly I mean this is a this is a constantly active tissue this is you burn a lot of calories at rest you know via muscle tissue so there four there's a and and plus you know to sustain something like exercise and movement that require requ Ires a lot of energy all right so as a result you're going to need to produce a lot of ATP so you can perform work all right so muscle tissue muscle cells have a lot of mitochondria neurons tend to have a lot of mitochondria they're very active cells as well I mean the brain you know in terms of total surface area of the body is one of the or or I should say size of organ is one of these smaller organs of the of the body itself but it's one of the most demanding organs metabolically of the body is as well all right so there's a lot of mitochondria in neurons all right to fuel the activity of the cell so so a lot of a lot of books and a lot of a lot of people that teach classes like this like the nickname mitochondrium the PowerHouse of the cell okay the PowerHouse of the cell the energy Factory of the cell okay and mitochondrian are unique because they actually have their own DNA okay when you look inside these these folds um called christe of the mitochondria there is actually DNA in here it's called mitochondrial DNA all right and what's interesting about this is they you know if you look at this from a Evolution standpoint you know it's it's it's believed that mitochondrian evolved from other organisms like some kind of bacteria there's a theory called the endos Symbian theory that that that describes kind of the beginning of where these uh complex animal cells came from you know from the fusion of a mitochondrian and then other parts to make a cell so I'm not GNA talk about that because that's not really relevant to this topic but it's just something interesting no look it up the endos Symbian Theory okay um endian here I write that down for you okay so that's what mitochondrian do for you all right so so if you put this all together all right you're starting to kind of get picture here you've got a control center that's used to that that's used as a code to make proteins all right and then you have all of this Machinery around here you have all of this Machinery that's used to synthesize proteins to package proteins to create proteins to be used by the cell that's the bulk of the job of a cell making proteins that's life folks I mean synthesizing diverse proteins all right and then the last organ that I didn't that I haven't talked about is the smooth endoplasmic reticulum see if I can get this to work for once ah close enough okay so the smooth endoplasmic reticulum which you see right here okay so basically the smooth endoplasmic reticulum is an extension of the rough ER all right the rough endoplasmic reticulum but obviously we call it smooth because it looks smooth in appearance it it looks a granular in appearance all right and the smooth endoplasmic reticulum has quite a diversity of functions I mean and it depends on you know what types of cells you're talking about okay so for example liver cells have a lot of smooth e okay hepatocytes all right because basically within the liver the liver is where we tend to deactivate steroid hormones and drugs all right so basically what happens are these drugs they get into you know they they get circulated in the liver eventually and then there are you know there because you got to remember these organel they're not like a part in the card these are packets that these are P complex packets that contain enzymes that carry out chemical reactions all right so the chemical reactions that occur in the smooth are are to basically take care of or deactivate or D nature render these nonfunctional okay so for example let's say you drink I don't know let's say you drink beer okay you drink some alcohol all right you drink some alcohol and what happens then is that alcohol is going to get into the liver and then the you know the enzymes within the smooth endoplasmic reticulum are going to break down the alcohol within the beer all right because you have to remember alcohol is an organic poison to us all right it just makes you feel good and do fun things if you have enough of it so now basically what happens now your liver is going to adapt to this because remember the nucleus is a site for synthesizing proteins not just to be exported but to be used by the cell itself all right so let's say I don't know let's say you're talking about building up a tolerance okay you build up a tolerance you hear about you know party animals in college talking about this or alcoholics okay so what happens then is as you consume more alcohol what happens is you develop more smooth endoplasmic reticul within the cell all right and then as you develop more of this smooth endoplasmic reticulum you're more acclimated to break down alcohol you're much better at it that's why a person has to drink more to you know get whatever you're trying to get out of the out of the booze all right and if we need to make that adaptation the DNA within the nucleus is going to allow that to happen because all we have to do is we make the right code to make the right proteins and then we you know you know create more smooth endoplasmic reticulum more enzymes within that ER and then we can handle that all right so I mean that's what the smooth endoplasmic reticulum does in the liver all right in in muscle specifically skel I'll use skeletal muscle as an example all right the smooth endoplasmic reticulum and SK in skeletal muscle is an area for calcium storage all right um in an area was called the SR the sarcoplasmic reticulum all right so basically uh what we do is we store this calcium within smooth muscle all right with smoth muscle within muscle and then when we need the muscle to contract the Cal the calcium is released and then we'll carry out the right physiologic mechanisms to um undergo a muscle contraction all right so that's so like I said the function of smooth are depends on what cell you find it in and these are just a couple of examples but for the most part it's used for storage or breaking down other you know other particles or molecules that aren't you that aren't really useful to us so that we don't need anymore all right so hopefully this kind of helps to paint a better picture of the cell itself and the Very and the main working parts of the cell and the overall job of the cell like you know as I mentioned you know the cell is the the whoops the primary purpose of the cell is for making proteins the nucleus is where the DNA is stored the Ruff you know making the proteins that be packaged and and excreted or the ribosomes that are used to synthesize proteins for the cell itself mitochondrian fuel you know generate enough ATP to fuel this process because as I mentioned earlier the proteins that are 25 to 50,000 amino acids in size the average size of a protein all right you know we have to expend one M you know one ATP molecule for every amino acid we synthesize so that's a very energy taxing process to make a protein so therefore we need an efficient organel like mitochondria to generate a lot of ATP for this process okay so again if you have any questions about this let me know and you know and I and I strongly encourage as you watch this video as well that you have your book open and some pictures of these um parts to take a look at them as I'm explaining them as well