Cell Structure | Summary

welcome to this video on cell structure summary this is intended to give you an overview of all of the parts of the cell no matter if it is a bacterial cell or whether it is an animal cell so of course let's get started with a little bit of coloring over here in this box we're going to talk about parts of the cell that I think of as being involved with manufacturing so like making stuff and shipping it out that sort of thing so let's go ahead and just highlight all the way around in pink of course right start with pink okay so here we go up here you're going to want to focus on writing fairly small and Title II because we do have a lot to put on this page so this represents the nucleus and the nucleus contains the DNA and that DNA is on what we call chromosomes and among other things that are less understood these the DNA codes for the making of proteins so this is DNA these on chromosomes and this represents a nucleus so we can maybe put an arrow like this and then notice that there's this little structure right here and this is the nucleolus and it literally means little nucleus and this is where ribosomes are made and I'm going to tell you what those are in a second here okay so then here are ribosomes once they are made and I think I'm going to switch to different colors it's looking a little boring so far so here let's put highlight in yellow you've got the nucleus and the nucleolus so far and then the next structures we'll talk about right here these are ribosomes and ribosomes make protein they take that code that's contained on in a nucleic acid form and they put amino acids together to form protein so we say that they make protein we could also say they do the process known as translation and that process of translation converts nucleic acid information in DNA into amino acid information that proteins are made of so that's why we call it like a translation it's literally going from the language of nucleic acid to the language of protein now notice that these ribosomes could be free in the cytoplasm so they can be free and the cytoplasm is the watery area that is inside of the cell so they can be free or they can be on endoplasmic reticulum so let's go ahead and make these Reds so you can see these are meant to be ribosomes that can either be free in the cytoplasm or on something known as the rough ER so let's go ahead and switch to another color and this is a membrane bound structure the rough endoplasmic reticulum and that literally means like a network of membranes within the cell and the rough ER is named if it has ribosomes on it and it folds and transports protein okay now let's compare that with other kinds of endoplasmic reticulum that are also in cells and see how this part right here that I drew doesn't have the dots on it it doesn't have ribosomes that's the smooth ER so I'm actually going to change colors because this would be a different structure found somewhere else in the cell but would not have the ribosomes so the smooth ER is going to make lipids for like cell membranes and it's really important in storing calcium which is the ion that when it comes out your muscles can contract so in skeletal muscles we actually call the smooth ER the sarcoplasmic reticulum so that's a term you'll hear at some point in your anatomy and physiology classes so I'm going to try to fit it right here of course I'm already running out of room but so the sarcoplasmic reticulum in muscles and that literally means the flesh membrane network and it stores the calcium in skeletal muscles and then when you have an action potential arrive at a skeletal muscle the calcium can rush out and cause your muscle to contract okay so let's switch colors again and now let's go to purple and this structure right here which were kind of I know we're inning out of room a little bit already sorry this is called the Golgi apparatus or the Golgi body it's the same thing and it's named after the scientists that first described and published it so the Golgi body or Golgi apparatus different books and websites will call it different things but what it does is it modifies and secretes proteins so you see how this all kind of goes with manufacturing you've got the code in the nucleus the ribosomes then make the protein the rough ER will then fold and transport those proteins often to the golgi where they get modified when I say modified I mean maybe they get a sugar added to it or maybe they get a lipid added to it and something that's important for that proteins function okay so then we'll move on to this structure here this is the cell membrane and I am including it I kind of went back and forth that I want to include it here or not for manufacturing but so often when a protein is modified by the Golgi and has like a sugar added to it it ends up getting inserted into a cell membrane so this is a cell membrane here and you'll also see that called a plasma membrane same thing so you can see cell membrane or plasma membrane and it is made of these these are here are phospholipids and remember we talked about the smooth ER making lipids it will make these phospholipids and then this right here is a protein so it has protein channels and those can allow things like ions whether it's calcium or sodium and potassium to go through depending on what kind of channel it is or glucose for example and then the phospholipids make up this is called a phospholipid bilayer and it's what makes up most of your cell membrane and I'll have a separate video devoted just to talking about the cell membrane because it's so cool basically so the cell membrane though is going to regulate exit entry and exit and it's also really important in maintaining what we call a negative membrane potential so I'm going to put here that so I'm trying to say this about the cell membrane so the membrane maintains negative potential and everything you learn about as far as like whether it's skeletal muscle contraction or your heart beating or an action potential firing you'll always come back to how our cell membrane can flip and flop its negative membrane potential and that's how it gets things done so that's why I don't want to make a point about that and then the protein channels are what allow things in or out but I wanted the membrane is what maintains the negative potential together so now let's go ahead to switch colors how about Back to Black if I can find out okay here we go so this right here is what we call a lysosome and I've tried to draw it for you like it's a garbage can or a recycling can it contains digestive enzymes to digest old cell parts or debris or it can even be involved in like disposing of viral parts in some cells so we make this that's add a little color along here right and then I put those little dots in there those are like enzymes that are capable of doing that here why don't we make the cell membrane orange just so we have a little more fun color on here okay so can't resist okay then the last structure I want to show you that when I think about manufacturing is that we also have a cell wall that sort of like the walls of the factory and it's going to keep some things from going in and out so let's go ahead and switch to blue and this is the cell wall and this is not found in animals so you don't have cell walls in any of your cells so cell walls only in rigid things like plants and bacteria so plants have them bacteria have them and mushrooms are yeast so fungi have them and then protists and animal cells do not have them so notice that this is a key difference so in and I'd like to add that down here that cell walls are not in all organism so we'll come back to that when we get done okay so let's move on now to another roll and this one I'll talk about for energy why don't we highlight this in green like I gotta go all the way down here we'll just do it like this it's like a maze a maze of color okay so energy the first one I want to point out here is a mitochondria mitochondrion is singular and I'm just going to highlight this oops my coloring is I have to move it down here for a second sorry okay so [Music] there you go so we'll outline that looks like my pen hang on okay sorry I just needed to move my camera up a little bit okay so the mitochondria is what produces ATP energy for your cells and that's adenosine triphosphate which is how cells get things done whether it's an action potential or muscle contraction or moving things in and out of a cell that are neat require energy ATP is the form of energy so this is like the fuel that your cells used to get things done now of course we'll use green to highlight this next energy organelle and that would be the chloroplast and they have these little stacks of green pigmented chlorophyll and this is how cell plant cells make sugar so of course we'll do this one in green so a chloroplast makes sugar and other nutrients they can make they can convert that into like proteins and lipids even like an avocado you know but they start by making glucose using absorbed sunlight energy so what a plant does is it takes sunlight energy it absorbs it with these green pigments called chlorophyll and chlorophyll is so those are the little pigments and then they make the sugar and then their cells are able to take put the sugar through the mitochondria to get ATP energy so a plant cell has both of these but I want to put a box around this one too this is another structure or organelle that is not found in all it's not found in you so let's go ahead and put that over here see how we wrote cell walls it's also write chloroplast because we'll come back to this at the end okay so then we'll talk about storage and why don't we use blue here because generally the central vacuoles in plants are filled with water so these are for water storage and if you have a plant that wilts it's means that the central vacuole in that plants in the plant cells is no longer filled with water and that's why plants will look wilted and then when you water them their central vacuole is fill back up and then they aren't wilted anymore so this is generally going to contain water but then in animal cells then actually it will go put it put this down here - or we had talked about this let's put this here - a centrist very specifically what's called a central vacuole so animal cells do have vacuoles a vacuole is just a little container to hold stuff so let's make these different colors though maybe an animal cell might contain some nutrients that it holds in one and then maybe it has some enzymes and another and maybe it even stores a little bit of lipid in a muscle cell for when you're exercising so it can grab it real quick so in animals now we'll just put a various substances okay so now let's go ahead and pick maybe purple for this next highlight so we can go ahead around storage like this and then go down down down down down down down down to the bottom of this one and then up like this and then we have a nice border for this last topic so this last topic is I put together structures and a cell that help with movement or giving it its structure so the first one I want to talk about is actin so actin is a protein that provides the structure of a cell so everywhere you see one of these little X's the idea is is that actin provides the structural framework for the cell shape so this cell right here is like an intestinal cell and you know how it has what are called micro villi on the top these little like see how it goes up and down the actin is what allows that so in your body all of your cells have different shapes and those different shapes are made possible by the way the actin is arranged to hold the top of the cell into a particular shape okay then the next thing we'll use yellow still for the actin so here is another roll of actin and that's in muscle contraction but along with the actin is another protein called myosin and that is going to be important in muscle contraction so actin and myosin overlap and shorten in muscle contraction so that's another example so these are what we call cytoskeletal elements actin and myosin okay then this one right here is a bigger kind of protein that works within a cell as a cytoskeletal element to Buell so microtubules are really big roads within cells another cytoskeletal element and what can happen is you have molecular motors us it says can he see kinesin or dining and I'll make that with a different color so this is powered by ATP and this molecular motor can move things around in the cell so microtubules are roads for molecular motors and then right here this is meant to be a vesicle so that's a vesicle a substance with some something in it that is being transported so let's say a protein or something so microtubules are cytoskeleton elements that line up in the cell and in order to allow things to move around now here down here this is these are all microtubules too so I'm going to use the same color because students often I think lose sight of the fact that when you're talking about mitosis and cell division this is microtubules these microtubules stretch out and they form these like long roads and they pull the chromosomes apart so right here a couple of terms that I think will come in handy for you this is what's called a centrosome and then each of these individual structures is called a centriole so we'll put centrosome with centrioles and these are important because they tend there only in animal cells they're not in plant cells so here is another one that we can put down here why don't we just put it right here send troops so sometimes you'll get a question about where these are found and these are not found in plant cells because they divide differently so these are chromosomes that are lined up and this these microtubules are known as spindle fibers but notice that everything you're looking at here that I highlighted in blue is made of microtubules so whether it is the centrosome with these two different centrioles or whether it's a microtubule that's moving something around these are all microtubules so I'm going to actually put this here made of microtubules so the cytoskeletal elements are important in the shape of the cell and muscle contraction and then in moving things around whether it's a newly made proteins that needs to be carried somewhere or moving chromosomes in order to divide a cell during mitosis okay so then as we wrap up I wanted to come down here and remind you sorry this is not my best looking video here okay alright so cell walls are only found in plants bacteria and fungi when I say that I mean like yeast and mushrooms chloroplasts I'm switching to green are only found in plants or sometimes in photosynthetic protists now there are many bacteria that can make their own food but they don't actually have the chloroplast organelle inside of them but they do have pigments that can make sugar and then the central vacuole is well known for its presence in plants okay then over here the centrosome and the centrioles are only found in animals and then I wanted to make a point of comparing bacteria or prokaryotes versus eukaryotes so all of these structures that we've talked about here are contained by eukaryotes so that's gonna be plants animals so things you would be familiar with right and then fungi remember that's things like yeast and mushrooms and then protists these are usually the ones students are least familiar with these are single-celled organisms that for example swim around in ponds and if you get a look at single-celled organisms in your general biology class you're usually looking at little pond protists and then prokaryotes don't have most of the things that we've put on this page and they basically include bacteria and then another type of protists or prokaryote is called archaea which is like specialized bacteria basically that live at really unusual places now they will only have the ribosomes they do have DNA but they don't have a nucleus and then the other thing that they do have is some rudimentary cytoskeleton but it's not what not called the actin and myosin necessarily that we have in eukaryotic eukaryotic cells so basically the prokaryotes don't have any of these structures except for ribosomes in their DNA okay that was a long one but hopefully we covered everything that you might encounter and then let me just back off a little students have often asked me if I would do this at the end of my videos you can see the whole thing so there it is and I'll even if I lower down a little bit without crashing it and then you can see there's the whole page okay good stuff see in the next video

Channel: Science with Susanna

Views: 42,534

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Id: tjx0TpCOoEA

Length: 25min 36sec (1536 seconds)

Published: Thu Jul 09 2020