hey everybody dr. o here in this video I want to give you a quick overview of all the organelles of a typical eukaryotic cell like our human cells so some of these will need some more detail and I'll do separate videos but this will be like a just a high-level overview I'm just gonna go right around the cell here like I did with the bacterial cell if you watch that video but let's go ahead and start kind of right near the top there with the cytoplasm so the cytoplasm is everything inside the cell inside the plasma membrane except for what's in the nucleus and some would argue about a few other details but really it's just the guts of the cell so the cytoplasm is the cytosol the fluid portion of the cell plus whatever organelles are swimming inside of it all right that's the cytoplasm the guts of the cell then you have the plasma membrane so the plasma membrane is a selectively permeable membrane and it's very important because it plays a role in keeping what we need in our cells in keeping what we need what we need out of ourselves out and then moving things back and forth so the plasma membrane I'll do it everybody I want it it's a phospholipid bilayer but it's it's very very important now what makes this unique versus the plasma membrane in a bacterial cell is our plasma membranes have cholesterol in them it's cholesterol is a dirty word in our culture but all of our cells have a neat cholesterol because cholesterol is what keeps ourselves from tearing open it's what makes our plasma membranes strong and they are so strong that we don't need a cell wall so plant cells don't have cholesterol so they need cell walls bacterial plasma membranes don't have cholesterol they need cell walls so we don't because of cholesterol so it's actually a really good thing in this context next this purple structure here we have the nucleus inside the nucleus is the nucleolus so the nucleolus is where our RNA or ribosomal RNA is made and then the ribosomal subunits are put together so it's a factory making the ribosomes that we'll need all over the place next in is just a nuclear envelope so it's actually really similar to the plasma membrane so it's a it's a membrane that houses and protects what's inside the nucleus which includes the nucleolus but also obviously your DNA your 23 chromosomes so that's the nucleus people call the nucleus the control center of the cell what I would say about the nucleus is this it controls protein synthesis if you or people call it the brain of the cell right if you were to ask me what's the brain of the cell I would say the plasma membrane the cell membrane is the brain of the cell it's what senses the environment and responds to what at what it's sensing in the environment so as far as like receiving information and making changes based on it I actually consider the cell membrane or plasma membrane to be the quote-unquote brain of the cell the nucleus though does control protein synthesis so the conversion of DNA to RNA and RNA into protein then lastly in this area we have the nuclear pore those are just the opening so that your RNA can leave the nucleus and go find the ribosomes here in our eukaryotic cells the next two are related we have the rough and smooth endoplasmic reticulum so they're both these they're both your kind of flattened chambers where materials kind of move through them but the key difference is the rough ER as it's called is studded with ribosomes so the reason it's rough is goods covered in ribosomes and the smooth ER is not that's why it looks smooth here so the rough ER think about ribosome where the ribosomes do as we'll get to in a moment they're responsible for the production of proteins or protein synthesis the site of protein synthesis so the rough ER think modification and packaging of proteins those proteins are being produced by ribosomes they're being modified and packaged there in the rough ER smooth ER doesn't have ribosomes so think nothing to do with proteins they make lipids like like part of your cell membranes that they make lipids and they make carbohydrates the other key thing that the smooth ER does is that it activates toxin so you'll see like the liver cells are gonna have way more smooth ER than a lot of cells so that's your rough versus smooth ER I'll come back to ribosomes again in just a moment because there are two different types of ribosomes I want to make that clear so that's rough endoplasmic reticulum and smooth endoplasmic reticulum next we have the cilia so cilia are gonna be on the surface of some cells just a note here bacteria don't have cilia so if you see a microorganism that has cilia on it it must be a eukaryote but so cilia are used for movement they they can actually if you're a single-celled organism they can propel you and move you through their environment but most human cells are gonna be connected to other cells in tissues and they're also going to be connected to connective tissue often called the basement membrane so if there are ciliated cells on our human cells they're gonna be moving material across the surface of the cell rather than moving the cell but the cilia think movement either the movement of a single-celled organism or the movement of material across the surface of a cell so very important examples we'll get to one organelle that's not on here that this makes me think of would be the microvilli so if the cell has there they're not as long as cilia and there'd be more of them but if a cell has shorter structures called microvilli villi means finger so imagine microscopic fingers microvilli their function is to increase surface area so if the cells gonna be absorbing or secreting a whole lot of material it'll often have micro villi on its surface we'll cover that when we get to histology that's the cilia next here on this image we have the Golgi complex I call it the Golgi apparatus but um another another section of flattened sacs what I think of it like as the shipping and receiving center of a cell so it takes materials and it modifies them alters them packages them and then puts them in secretory vesicles so they can be sent out of the cell that's why I think of it kind of like Amazon warehouse or something like that where it's taking material it's putting tags on it so this material knows where it should go and then it's sending it out into the world so that's that's the golgi complex or Golgi apparatus peroxisomes so they're going to they're going to help break down fats or other organic compounds but the key thing here is not only can they do that but they neutralize the toxic byproducts that happen during that when fat you know think about fat like going rancid right when fat breaks down it does produce toxic products so the proxy zone can break down these materials but also neutralize any toxic products part of the reason that our cells don't um don't wither and die in aged way too quickly so that's the peroxisome next you have the lysosome I personally this one's more important I always call this the digestive system of the cell think of it like a stomach it's a bag basically with dozens of digestive enzymes in an acid so just like your stomach has acid and enzymes the lysosome has the same thing so this bag of acid with digestive enzymes like there's 40 to 50 of them there's argument there but lots and lots of different enzymes so it can break down a whole host of things it can break down like like food stuff but it can it can break down bacteria that get in the cell but one of its major functions is it breaks down damaged organelles so one of the reasons that ourselves can stay alive so long is when organelles have been damaged they're broken down and replaced and the lysosome plays a major role there so lysosome think digestive system of the cell next here we have microtubules so this real quickly microtubules and then a few over there microfilaments those built make up your cytoskeleton the skeleton of the cell the difference as a micro filament is a solid structure and microtubule would be hollow but think they help they help give the cell shape but they also help with the movement of materials so things can actually be carried along their surface so thank cell shape cell structure but also helping move material through a cell but they're relatively minor all right that's the microtubule the mitochondrion or mitochondria this would be the powerhouse of the cell so think about like a coal-burning power plant or something like that this is where 95% of your cells ATP which stands for adenosine triphosphate is going to be produced so the reason it's 95 percent is as we'll cover in the sections on metabolism glycolysis doesn't happen inside the mitochondria so those first couple ATP are produced outside of the mitochondria and the rest are produced inside of it so mitochondria think powerhouse of the cell 95% of ATP is produced here give or take all right that's the mitochondria next we have the ribosome so the ribosome site of protein synthesis or the site of translation if you want to use the more technical term key thing here so as I covered in the bacterial cell structure video our ribosomes most of them have a different shape than bacterial ribosomes this is why so many of our antibiotics attack the 70s ribosomes of bacteria because our ribosomes are called 80s ribosomes or 80 fed berg units I don't care about that term that's not 100% true though because our mitochondria which you has talked about they do have their own ribosomes and they are 70s ribosomes so it's kind of an interesting fact so ribosomes think protein synthesis or translation but very important here I want you to note that there are two types of ribosomes free ribosomes and fixed ribosomes so the little dots that are off on their own are called free ribosomes the the the ribosomes that are on the surface of the rough endoplasmic reticulum those would be fixed so they're attached to something else here's the key difference free ribosomes think proteins are being produced that are going to be used in this cell by this cell fixed ribosomes are going to be proteins that are going to be sent out of the cell so if the cells making a protein that it needs it would be used it would be using a free ribosome if it's making let's say this is a pancreas cell and it's making insulin insulin the protein will be made by a fixed ribosome and then modified and packaged by the rough ER and sent to the golgi and then secrete it out into the into the body so that's the two types of ribosomes free versus fixed I already mentioned microfilaments just a couple more here the centrosome is where the two your two centrioles are so every centrosome has two centrioles sitting at a right angle to each other and these are necessary for cell division they actually you this is they they align and pull your chromosomes apart during mitosis so you so as if a cell doesn't have a centrosome or doesn't have centrioles which is the term i'll use more often they can't the cell can't abide think about like most of your neurons for example so that's the centrosome and the two centrioles that are in it then we have the flagella so our flagella is really just just two contractile whip-like flagella versus the rotary motor system of a of a bacterial cell so it's actually an area where they're their cells a more complex than ours but flagella think movement and that's all of them I know that's a lot so I you know got this video a couple times and like I mentioned I will make more detailed videos on the on the organelles that need it okay but that's a nice walkthrough of the parts of a eukaryotic cell like our human cells have wonderful day be blessed