in this video we're learning the parts of the cell now I remember first learning this stuff and memorizing each organel and a little description of what that organel does but I never understood the big picture of how these things work together to help the cell accomplish its functions and that meant that my understanding of the cell and my ability to recall this information let's say on a test was pretty limited so what I want to do in this video is tell the story of protein synthesis or the making of proteins as well as a few other cell functions so that whenever you learn each organel and what it does you're going to understand how that all relates together and the different processes that the cell has to do you're going to understand the cell way better than you ever have so let's jump to whiteboard and get started the first thing I want to talk about is the cell membrane so our cells are these kind of these little bags of fluid and like any bag it's got to have some like surface around it to keep all of that fluid in and that's our cell membrane if we zoom in on the cell membrane it's going to look something like this now don't click off the video being like Oh my gosh this looks super complex the main thing I want to point out with this is that most of the cell membrane is made up of this phospholipid bilayer in red we has phosphate molecules and in the yellow right there yellow orange is going to be lipids so these are phospholipids and it's a bilayer there's two layers of them and this is going to be the membrane that keeps all the fluid in now if you look at this there's a bunch of other stuff embedded into it and these are all going to be proteins so we have a protein here we've got a channel protein that can allow certain things to pass in and out lots of proteins in here but the main thing this is a phospholipid bilayer membrane that's keeping all of the stuff in if this membrane ever ever ruptures or breaks all the fluid and all the stuff of the cell would leave and that cell would no longer be able to carry out its cell functions it would it would die now the stuff inside the cell we call cytoplasm that term cytoplasm cyto just means cell and plasm just means fluid so cytoplasm is the cell fluid the next organal we look at we're going to look specifically at this process of synthesizing or making of proteins synthesis means that you take multiple things and put them together in some new form that's kind of what we do with proteins we take amino acids and put them together to form a new protein so let's take a look at some organells that are involved in this process the first one we want to look at is the nucleus so the nucleus most cells are going to have one nucleus and the nucleus itself has its own membrane we call the nuclear membrane or the nuclear envelope and inside of that nucleus is chromatin now you may think of chromosomes aren't there chromosomes in the nucleus well most of the cell's life it's going to be chromatin which is these kind of long curvy strands of DNA it's only when the cell divides that that chromatin forms forms into chromosomes but most of the time it's in the form of Chromatin this is your DNA or genetic material and that's going to be inside the nucleus so what does that DNA actually do well in the nucleus the DNA gets transcribed into mRNA transcribe just means to take something and make a an almost exact copy of it now if you already know about transcription you know that it's not an exact copy it's making a copy of the opposite nucleotides but for the purposes here just think about it as an exact copy of of a section of the DNA and this mRNA is going to code for a protein basically each mRNA is going to be instructions for one protein molecule so in the nucleus we convert DNA into messenger RNA or mRNA next we have something called a ribosome the ribosomes are super small and they're spread throughout the cell I got them drawn in two clusters right here but they're really kind of spread out more than that in the cell and what's going to happen is that mRNA is going to travel to the ribosome and the ribosome is going to read the MRNA instructions and uses instructions to build a protein now here's my favorite metaphor for this it's building Legos I've got a Lego R2-D2 um in the background right here that you may or may not have noticed but whenever I built that I had to read instructions and the instructions told me which bricks to combine in which order in order to make R2D2 in this metaphor the MRNA is my instruction booklet telling me what to do I'm the ribosome because I'm building the protein which is the finished Lego structure and each Lego brick is an amino acid when you combine the amino acids together in the right way they form a whole protein and that whole process is taking place in the ribosome here is the ribosome it's reading the MRNA so the MRNA is feeding through the ribosome right there and for every three nucleotides that reads on the ribosome it's going to add in one amino acid so right here it's going to be building out this long chain of amino acids forming a protein each amino acid being one of those kind of orange circles right there so our created protein at this stage is going to be a long strand of amino acids now it's got to undergo some other changes before it's ready to to actually do anything in the cell but that's the point that we're at right now once we're done in the ribosome so our nucleus contains our genetic information which is going to get transcribed into RNA in the nucleus mRNA is going to travel to the ribosome where our ribosome will read it and then use those instructions to build a protein from amino acids now where do these ribosomes come from well we've got a lot of ribosomes and we have a special structure that's going to make those ribosomes and that special structure is the nucleis so the nucleis lives in the nucleus but its job is to make the ribosomes it's basically a little ribosome Factory all right where do our proteins go next after they've been created in the ribosomes well we have another structure here called the rough endoplasmic reticulum and the rough endoplasmic reticulum is going to be dotted with more ribosomes all throughout the ER are going to be ribosomes and that's why we call it the rough endoplasmic reticulum when you look at a cell on the microscope the ER the rough ER looks rough because it's got all these dots on it which are the ribosomes the main thing that the rough endoplasmic reticulum does is it's going to be modifying the protein at some point the protein got made in a ribosome and it passes through each of these layers and as it does it's going to get Modified by the rough ER now when we say modified what do we mean I've got a list of four modifications I want to talk about one is it'll do the initial folding of the protein so at this point we've got this long strand of amino acids which is our protein but the actual proteins aren't just a long strand most of them they're going to be different kind of three-dimensional structures they could be a channel and the membrane that allows stuff to pass through it could be a receptor on the outside of the cell membrane it could be an enzyme that binds with a molecule and breaks it apart it's got to have a 3D structure and we get that 3D structure by folding the protein the Ruff can also do quality control and so if it discovers a protein that's different than it's supposed to be the ru can destroy that protein it can also do something called glycosilation which is a fancy term that just means adding a glucose or adding a sugar that glyco just means sugar and so a lot of our proteins are going to have other things added onto them so glycosilation or the adding sugar that'll happen in the ru ER we can also do destination tagging so the Ruff ER can tag the protein molecule with another piece that's going to tell the rest of the cell where this protein needs to go so is this A protein that needs to end up on the cell membrane is this A protein that needs to end up in some other organel in the cell or is this A protein that needs to leave the cell in order to go bind with a structure on some other cell in the body in other words is it a hormone so these are four modifications that can happen in the rough ER but the big thing to remember here is that the rough endoplasm reticulum is going to be modifying these proteins getting the proteins ready to go out and do their function what's next after it goes through the Ruff it's going to be packaged and sent to the GGI apparatus it's got two sides to it it has the CIS side and the trans side and that protein which has been made by the ribosome and then passes through the rough endoplasmic reticulum it's going to pass through the CIS end and then out the trans end what the GG apparatus is going to do is it can do further modifications so if there's any extra modifications that need to happen before it leaves the cell it can do that it's also going to package it in a vesicle so they can send it to wherever it needs to go so the GOI is going to modify and package that protein to send it out to where it needs to go it's kind of the FedEx or the UPS of the cell now where are all the places that can go for one it can be sent to the cell membrane because we have all these membrane proteins if you remember this diagram from earlier we've got all these proteins in the cell like this channel protein that can allow certain molecules to pass in and out of the cell another place that the G Center protein is actually outside of the cell so it'll package it in a vesicle we've got an example vesicle right here the vesicle is going to travel to the membrane and kind of form up with the membrane like this through the process of exocytosis and send those proteins outside of the cell to go do some function or it could send them to some other organel within the cell now there's a lot of different places that can go in the cell the one I want to talk about though is the smooth endoplasmic reticulum one big difference to remember about the smooth obviously is it's not rough so it doesn't have ribosomes on it but not only that its function is very different whereas the rough ER was focused on modifying the proteins the smooth ER is going to be making or synthesizing lipids and carbohydrates now wait wait wait wait we just said we send proteins to the smooth what does that to do with making sugars and carbohydrates well if you think about proteins what are proteins they can do a lot of different functions one of those functions is to be an enzyme an enzyme is going to facilitate a chemical reaction and whenever we're making a new chemical such as synthesizing a lipid well we have to have enzymes to actually facilitate those chemical reactions so we have special proteins that are made sent to the Smoothie R so that they can work to make those lipids and carbs that we need so even though way back at the beginning of this process we have instructions from the nucleus on how to make different proteins but really those instructions on making those proteins will also influence what lipids and carbs were able to make so it all comes back to that DNA all right let's do a quick recap of this process so the nucleus contains our genetic material our DNA which is going to get transcribed from DNA into mRNA the MRNA will travel to the ribosomes which are made by the nucleolus the ribosomes are going to translate the MRNA read those instructions and assemble a protein out of amino acids the protein will travel through the rough endoplasmic reticulum as it works through those layers it's going to get modified in different ways that'll be sent to the GGI apparatus and get packaged where it will travel to wherever it needs to go that could be to the cell membrane it could be outside of the cell or could be to another organel such as the smooth endoplasmic reticulum whose job it is to synthesize lipids and carbohydrates for the body next we're going to look at converting food energy into ATP now this may be the one organel that you already know from seeing memes online and things like that and that's going to be the mitochondria you've probably learned it as the PowerHouse of the cell so the mitochondria are going to be producing energy but nothing can produce energy out of thin air right it can't be created or destroyed and so we have to be converting it from one form to another so how do we bring energy into our body well all of this is governed by this reaction so we have sugar right here basically we've got food that we're bringing into our body and we have oxygen that we're breathing in we're going to take both of those chemicals and put them through the process of cellular respiration and we're going to be converting that into the things that we get rid of such as carbon dioxide that we breathe out as well as water but the big thing right here that we're doing is we're producing ATP so we're taking these kind of higher energy molecules we're going to break them apart and then reform them into these lower energy molecules which will release some energy and that energy that gets released we're using that to produce ATP which is a usable form of energy our cells the the pumps and channels and stuff in our cells can use ATP to power all the different functions that we have in the cell and that whole chemical reaction is taking place in the mitochondria fun fact about the mitochondria the mitochondria have their own DNA which is different than the DNA that is contained inside of your nucleus and all of your mitochondria you got from your biological mother none of it from your biological father which is different than the DNA in your nucleus which is a combination of your biological father and biological mother's DNA mitochondria are pretty wild all right let's go on to the next function that next function is going to be the storage and breaking down of chemicals we've got three organel that are all kind of similar here they're going to be involved in these different processes the first one is a lome that pre fix lice or sometimes light like cytic lice just means to cut something open or to break it apart so a lome is going to contain a bunch of enzymes that we can use to break down different molecules that enter the body this could be a pathogen that's entered into the cell and the lysosome will spill out its contents in order to break that thing down it could be an old organella that we no longer need that we're going to use the lome to break it down or sometimes we'll go through the process of apoptosis which is where a cell decides to destroy itself and so it'll use its own lomes to destroy itself an example of that would be like an infected cell that needs to doesn't want the infection to spread so that cell will break itself down now those enzymes in the lome where do those come from well remember enzymes are proteins so these were proteins that were made by the ribosomes which were coded for in the DNA of the nucleus which then passed through the ER and the Gogi apparatus and then ended up in the lome so it's even the lome the proteins in there are connected to that process we looked at at the beginning of the video next we have something called a peroxisome a peroxisome is kind of like a lome but instead of breaking things down it's going to work to oxidize or to neutralize some toxic substances a big example of that is hydrogen peroxide which is where it gets its name from to remember this just think perox and detox it'll detoxify certain chemicals that end up in our cells and then finally we have the vacu the vacu is just going to be for storage of different chemicals plant cells have giant vacul that fill up a majority of the space inside the cell animal cells like those in our bodies have small vaces for just small amounts of storage but certain cells like fat cells in our body will have larger vacul because they're going to be storing fat molecules but then a lot of other cells will just have small vacul inside so vacul are for storage the next process we're going to look at is the process of reproduction which is really going to be either mitosis or meosis I say meosis some other people say meiosis if I'm saying it wrong just let me know in the comments I I know somebody will now I've grayed out a bunch of organel in the diagram the one that aren't quite as involved in this process but the ones that are heavily involved in the process include the nucleus of course cu the nucleus has the genetic information and both copies of the cell during mitosis need a copy of that genetic information I've got the cell membrane here still because both new cells are going to have each their own cell membrane and so that cell membrane has to kind of divide and pinch off into two new cells and there's one organel that we need to add which is the centrosome the centrosome looks like this and it's actually going to be two parts to it it's going to be two centrioles so right here we have one cental and then another cental kind of organized at a 90° angle to it and what the centrosome is going to do is it's going to grab onto the genetic material the chromatin which will become chromosomes during mitosis and pull those apart so let's take a look real quick at what that process looks like so here we have the chromatin and during mitosis it's going to separate out into chromosomes which look more like this and our cell's centrosome is going to make a copy of itself so we'll have two croomes now and those are going to form one at one end and another at the other end and they'll use these fibers to grab onto the chromosomes and pull them apart so that each new cell is going to have its own copy of the chromosomes and here we have those two new daughter cells that each have a copy of the genetic material that's how cells make an exact copy of themselves of course we also have this process of meosis which is how our bodies create sperm cells and egg cells Each of which are going to have just a half of the chromosomes but again the centrosomes will line up on either side of the cell they're not drawn in that diagram but they're going to pull the chromosomes apart and again involved in that process are the centrosomes as well as the DNA or the chromatin and the nucleus and the cell membrane okay our next function that we're going to look at is the function of structure and movement so the first one I want to talk about gives it its structure and that's the cytoskeleton again CYO just means cell so this is the skeleton of the cell and it's made of two main parts it has m microtubules as well as filaments the microtubules look like this they're these long thin fibers that are going to originate from the croome right here and they're going to connect all the organel together so these organells aren't just kind of like free floating and wandering around the cell they're held in place by these microtubules and those microtubules are made of proteins so that'll give the cell its main structure and then on the outside of the cell we have something called filaments now there's really two types of filaments here there's intermediate filaments which are going to be more kind of close to the microtubules and then we'll have microfilaments which are going to be more on the outside of the cell against the cell membrane but I kind of simplified it here and just called those the filaments so we have the microtubules holding things in place and then we have the filaments around the outside of the cell providing some more structure let's add a few more things to our cell here some cells have structures called microvilli the microvilli are just going to be these foldings on the cell membrane purpose of microvilli is going to be to increase the surface area of a cell so not all cells have these but an examp example of them is the cells in your small intestine your small intestine has to absorb molecules that you eat and so we need a bigger surface area so we can absorb more molecules so those cells are going to have microvilli another structure on the outside of the cell is p cyia the big difference between cyia and microv is that they contain microtubules inside of them at the base of them there's going to be something called a basil body which is basically a cental and what these microtubules inside the cyia are going to be able to do is allow the cyia to have some movement so they're going to wave back and forth so the cyia can move mucus around and move air around and different things we find cyia in places like our lungs like the bronchioles in our lungs one more movement related structure I want to talk about here is a flagellum a flagellum is basically the same thing as cyia but rather than having a bunch of cyia it's just going to be one projection but it's also going to be filled with these microtubules the only human cell that has a fum is a sperm cell and so those microtubules in there are going to have kind of a rotary motion like this which is going to propel the cell to where it needs to go all right we've covered a lot of stuff in this video I want to give you a chance right now to practice all of this stuff so pause the video see if you can name all the structures on this part of the diagram and then here are those structures back and now let's take all of those away and let's go back to our diagram before this see if you can name all the structures in this diagram and even better see if you can explain the process of protein synthesis in terms of all these different organells and then here are all those organells back so you can check and see what you remembered if you're learning all this stuff for a class the only way to learn it all is to practice it and to make sure that you're using the best strategies to practice I have a free A&P survival guide link in the description for that it'll just give you a bunch of strategies for how to learn A&P and make sure that information sticks with you I've also got some other resources such as& study cards including blank versions of the diagram in this video I have other comprehensive unit guides that can help you if you're studying like the nervous system digestive system Etc links in the description for all of that special thanks to my patrons on patreon as well as my YouTube channel members thank you so much for your support of the channel I really appreciate it hey thanks again for watching this video and learning about the cell hopefully you understand the cell better than you ever have here's another video that you might find helpful thanks again for watching and I'll see you in the next video bye-bye