hi uh we're back again here with some of our fundamental information and today we're going to be looking at cells and cellular processes and some different features of cells so the first thing we're going to do is we're going to start off here and again this is our roman numeral number one uh which is our new subject area and we're going to start looking at essentially what was called the cell theory so in cell theory here basically we know that all living things and obviously including humans here are composed of cells so all living things are composed of cells and we're going to state that the cell is the fundamental or basic and functional unit of life so there are a number of things in anatomy that you'll see that basically tell us that these are sort of structural and or functional units of different kinds of things and so this is obviously one and of course when we're looking at structural functional levels of organization we're going up now into our cells and organelles our second and third levels of becoming more and more complex and the third thing that happens here is that all cells come from pre-existing cells in other words there is no what we call spontaneous generation here of of life so different things are going to be happening here in terms of how um how this works so everything comes from pre-existing cells so in other words every cell in your body so every single cell in the body is a direct descendant a direct descendant of the first cell we're going to talk about this when we get to embryology this cell by the way is just called the zygote so you probably know that already so this is the fused egg and sperm that occurs and we'll talk about that and then cells become what we call differentiated so differentiation is the process of becoming different literally just becoming different so different cells become differentiated in other words they turn into different kinds of cells their skin cells there are liver cells or kidney cells all those different kinds of things so that's kind of what we're we're looking at here for for this so a couple different things there are different estimates about how many cells are actually in the body and there are estimates that sort of range from pretty close to about 40 trillion to about 100 trillion most scientists agree that it's somewhere around 75 to 100 trillion cells and of those and this is just sort of an interesting sort of g whiz fact is that about 25 trillion of those cells are red blood cells and most you probably know that red blood cells carry oxygen right they carry oxygen so uh anywhere from you know maybe a half to you know a fourth you know somewhere in that range of all the cells in your body are the ones that are so important in terms of carrying oxygen so a couple of different things about this that i want to want to mention bring this up a little bit here is let's talk a little bit about what we call the cellular environment so this is the cellular environment so what we mean by by this here is what kind of environment is the cell actually existing within and around so a couple different things about this that are important one is that approximately two-thirds make that better two two-thirds of the fluid and the body is inside cells so it's actually inside cells and this is known as the intra and the prefix intra it means within intracellular fluid and we abbreviate that as just icf okay icf intracellular fluid so this is the stuff that's actually in there and again we said that uh water comprises somewhere around 60 to 70 percent of the body so a good portion of this fluid is made up of water it's not the only fluid that's in there but it's most of that now the implication for this though which i think is really fascinating is that that means that the other one third of the fluid in the body is outside of cells so this is going to be found outside of the cells and this fluid here is known as extra extra meaning outside of extracellular fluid and of course we relate that as ecf okay so ecf so excited fluid and this is really really important because uh we often think that our cells are all stuck together but in fact there's a lot of cells that are that are not you'll find out about that a little bit a little bit later on now when we look at the extracellular fluid here there's actually this fluid is found in two different kinds of compartments so two different kinds of of compartments that we have this in the first is about 20 to 25 percent is what we call the blood plasma so a lot of times we don't really think about the blood plasma as this kind of fluid but it is it's extracellular fluid and about one-fourth of this one-third here somewhere between a fifth and a fourth is actually found in the blood plasma the other basically 75 to 80 percent is what we call inter interstitial whoops make sure i spell that correctly so again here's that word enter which means between as opposed to intra which means within and i always remember that because enter has an e in it and so does between has lots of e's stitial here is an interesting thing so the ending al always means pertaining to or relating to and whenever you see something that says stishum or t-i-u-m-c-i-u-m s-i-u-m it means tissue so this is interstitial fluid and we abbreviate that as isf so that's the other part that's the stuff that's actually between the cells so this is the material that's actually between the cells so very very important stuff and we're going to come back to this a number of times so you really want to sort of understand these compartments so when we look at a couple of cells here something like that here's our icf and here is our isf right in between and if we have blood vessels running between them inside of that is going to be our plasma our blood plasma so we want to kind of keep that in mind and these two fluids here are extracellular these are of course intracellular itself okay for that okay let me move this out of the way here okay so what also do we know about this okay so there are a couple of different things that i think are also important and useful to know is that when we look at the icf there are lots and lots of things in this intracellular fluid that's that's here but one thing i want to have you uh sort of focus on is that there is lots of potassium so lots of potassium remember last time we talked a little bit about potassium itself so this is an abundant ion so when you're you know drinking orange juice or having a banana or something like that that has lots of potassium in it most of it ends up inside of cells so that's where it goes all that is going to be inside of cells so we're going to have lots and lots of that potassium inside of these cells now in the ecf and this is in both compartments both blood plasma and the interstitial fluid here we're going to have lots of sodium ions so when you have something that's really really salty you know say one of your favorite meat lover pieces pizzas or something like that you're going to get lots of sodium that's going to exist out here so here we're going to find lots of sodium out here now of course these are not the only ions that are there and there's other things that are that are part of that but i kind of mentioned last time that sodium potassium are very very important and the relationship between these is is very important one as as well and so i don't want you to sort of you know miss that and sort of understand that we'll come back to that occasionally a little bit later on we do a lot more with this in physiology but it's important to sort of understand how cells work in different places and part of it is based on this distribution of lots of sodium ions outside lots of potassium ions on the inside so what is the implication of all of this okay so we can say then here that all cells live or exist a and we'll say more or less similar environment there are some you know differences here and there for different kinds of tissues but for the most part we're going to have cells that are surrounded by ecf right and sometimes a lot sometimes a little but that's an important aspect and it turns out here that cells attempt because they are functional units here both structurally and functionally important and what they do is they attempt to maintain a again more or less similar environment even if here even if conditions change and this concept here is known as homeostasis so the derivation of this homeo means similar not exact otherwise we'd have the prefix homo here homo and stasis means status right so this is a more or less similar environment even if conditions change and your conditions are changing all the time within the body every time you eat if you're running up and down stairs you know or you're playing some sports or whatever it is things are going to change and your body tries to maintain this fairly similar environment both inside of cells and outside of cells and in fact homeostasis is the founding principle for physiology so we're not going to spend too much time on that but you sort of want to understand that so when you take physiology we talk a lot about homeostasis and the way that those are are put together so the body has to monitor all different kinds of factors to maintain this homeostasis things like blood pressure and hormone levels and temperature and and oxygen content and and carbon dioxide content within cells so this is a very very important feature for for all of this okay so let's take a look here at the organization of the cell so the organization of the cell how is this thing sort of organized there are basically three main components and the first component that we have here is called the plasma membrane sometimes just known as the cell membrane and we're going to abbreviate this as the pm that way we don't have to spell it out all the time and again the other term here is the cell membrane so we'll use those interchangeably and there are other membranes that exist that surround and define organelles as we'll talk about but this is the one that's on the outside of the cell okay so this will say sort of defines the morphology of the cell and you might recall from last lecture that we talked about morphology as sort of the size and the shape or dimension of the cell and so there are a variety of different kinds of components that comprise this and again there are great pictures of this uh that are found in your textbook and also uh in the web lecture as well so you know i want you to refer back to that as well so first of all this is a dynamic structure so a lot of people think that oh this is like you know some kind of wong or something like that that just stays the same all the time it has the same bricks or fence or whatever you want to sort of use as your analogy here but this is a really dynamic structure it's changing all the time in terms of shape and where it is and it's defined by what we call the fluid mosaic model so this structure is the fluid mosaic model so it's fluid it's going to change mosaic means that it has different kinds of components sort of moving around each other at different times so the landscape if we look on a piece of the uh of the the plasma membrane is gonna actually look a little bit different at different times so i sort of like to think about that so this is a dynamic structure always changing it is mostly composed of lipids and in fact these lipids form as a by layer so by layer double layer here and this double layer here is sort of shown um graphically kind of like balloons here let me show you this so these balloons here with a couple of little squiggly tails and because we have this bilayer they're going to look like the opposite so here for example this would be the ecf out here this would be the icf here and so these are these various kinds of lipids we mentioned fatty acids that's what these little squiggly lines are and there's a specialized these bubbles here are specialized uh parts of that called the phosphate portion of that through sort of an organic phosphate grouping of those things and when if you take a bunch of these and you throw them into a solution they automatically align like this they actually form a bilayer on their own and so there's some repulsion here because of the polarity of these cells it turns out that there is kind of a negative on the outside here these little bubbles are sort of negative and negatives and negatives will repel each other and so they're going to force this into this bilayer of of lipids and so we call this a bilayer of phospho lipids more formally and most membranes even organeller membranes are sort of organized this way as well now within this layer here we're going to also have embedded proteins and they're all different kinds of proteins and in this course we're not going to really worry too much about about those the different kinds and stuff but they have a variety of different functions they work in a number of different ways so while we sort of look at these is kind of twofold one is what we call the transmembrane proteins so the transmembrane proteins which means they go all the way through from one side to the other so they can go all the way through from the icf to the ecf here and then we also have what are called peripheral proteins and peripheral force means to the side here or around the sun and so those are always found on the icf side virtually always on the icf side so they don't go all the way through and they're not actually attached to the plasma membrane per se but these embedded proteins here are ones that are sort of you know within uh within these just like that now there are some specialized aspects to some of these different kinds of proteins and i just want to mention a couple of of these sort of types if you will so we'll say types of proteins and there are basically three of them so and they have again different kinds of roles here which we won't get into too much a little bit later on but not too much right away and some of these are called glyco proteins and the word glyco refers to sugar or different kinds of carbohydrates and so these sugars are like little branched areas so if we have a protein here for example we'll see this is our our protein we might have a bunch of little sugars that are kind of attached kind of like this here and they might be branched kind of like that and so these are the sugars and this is the whoops sorry sugars here and these are the this is the protein so attached to to that this would be the protein here and again what we would have uh in this is slow our you know layer of bilipids kind of like this right and they would be on either side here kind of like that okay but these again would be sticking out and this is always going to be on the ecf side so again this is on the ecf side portion of this then we also have what are called glycolipids so again sugar and lipids here again these are going to be on the ecf side here so they're going to be sticking out so here these are going to look something like this so let me just do a little thing here kind of like this and we might have a different different type of set of sugars coming off of this that kind of look like that so again here are the sugars and this would be the lipid portion here like that whoops all right so there we go miraculous stuck on that okay so again a couple of different kinds of things and maybe somewhat surprisingly here is we have this molecule cholesterol we hear so much about so cholesterol also is a structural protein that's found within these these areas in here like that and they're scattered throughout so we might find them you know pieces of cholesterol here cholesterol here we might find cholesterol over here go back up to here and show cholesterol in some different places here so these are going to represent the cholesterol and so this is within the bilayer of lipids so it's not on the outside it's not on the inside it's actually within the bilayer of phospholipids that we have for this so that's gonna you know sort of represent our cholesterol just like that okay so that shows us a little bit about this now one of the other features about this that's very important we'll finish up with our plasma membrane here is that this membrane is called semi permeable and sometimes it's also known just as selectively you'll hear this term selectively permeable and so just selects different things it basically controls what you go in and out of of cells so it controls what can actually go in and out of cells it's mostly based on size not completely but it's mostly based on on size for for this okay so now let's look at our second main component and we have remember there are three components that comprise the cell our second component here is the cytoplasm and the cytoplasm basically contains the organelles so as i said we talked about structural and functional levels of this that we sort of do this together with cells as our second and third levels of structural and functional uh organization for for this okay so let's talk a little bit about the cytoplasm per se what is this stuff okay so cyto of course refers to cell plasm is sort of a semi-liquid semi gel okay so we'll just say that it's a semi liquid semi gel i always sort of think of it like sort of that clear hair group that you can put in your your hair and it's kind of liquidy it's kind of you know gooey and sticky but at the same time it's got a lot of water in it here and again this is a lot of what the icf is and of course a lot of the icf is water itself okay now the fluid portion the actual fluid portion because there are solids in here as well so the fluid portion is known specifically as the cytosol okay cytosol so saw referring to kind of solvent if you will and so where things are dissolved with within it that's just the fluid portion and this is also where a lot of action occurs so this is where most metabolic reactions occur so this is where most metabolic reactions are going to occur this is where it's mostly happening in the cell and so let's talk a little bit about metabolism here for just a moment we can define what metabolism is and we can define the metabolism actually in the whole organism in an organ system an organ down to tissues or cells themselves even within organelles and what that really means but we're going to sort of use the all-encompassing idea of this so this is the sum total of all chemical over here chemical reactions and we can say in the body or if you want we can talk about it with regard to the cell since we're talking about cells right now so it could be within the body or the cell itself so it's the sum total of all reactions and it turns out that there are two different kinds of groups of reactions that occur the first type is what we call catabolism these are commonly known as the catabolic reactions so catabolism here is all reactions so all chemical reactions involving breaking down so anything that breaks down something from a larger molecule into smaller molecules so let's say we have a little molecule here and we undergo a chemical reaction and now we've got a couple of different pieces maybe even three parts of that we're breaking that down into three other chemicals or two chemicals or whatever it is how many other chemicals that's a catabolic reaction the opposite of that is called anabolism and these are all reactions involving building up so everything building up so here we're going actually in the opposite direction right we're taking small molecules building larger molecules so here this would be considered to be catabolic and this would be anabolic and you've probably heard of things like anabolic steroids that sometimes weight lifters and others take and what that does is it allows them to again presumably get larger their muscles get larger here anabolic steroids has a lot to do with protein synthesis uh and so it helps in that that process uh for that to to occur okay so let's talk a little bit about some of the organelles that occur within here and we're just going to talk about some of the main organelles and again there are really nice pictures that are found within the the textbook and also the web lectures for you to look at and of course millions of on the on the internet as well i'm going to move this up just a little bit let's talk first about what is called the endo plasmic reticulum and abbreviated as er thankfully i have to write that all out so endo again is another way of saying inside plasm referring to the cytoplasm a reticulum is a network right so when anatomists were first looking at this through microscopes uh they saw this really highly dense network of of membranes that were there they weren't quite sure what it was and of course now we know what this is so here these are a series of flattened or tubular membranes so again these are made out of membranes here and these the er is connected to the nuclear membrane so this has a variety of different functions and uh one of the things that it does here is to be used as a rapid transport system so we can say that in part functions in rapid transport so it's kind of like the freeway system in the cell because the cell is very very dense when you look at pictures of that you'll see that it's really really highly packed with a lot of stuff so we need a a place kind of like side streets right we can't go quite as fast in general and as long as things are flowing well on the freeway we can actually move in a pretty good clip and get from one area to another area pretty pretty quickly through the uh the cytoplasm itself now there are two different types of this er so we'll see types of er and they have a variety of different functions we'll just talk about their main functions first type is what we call smooth endoplasmic reticulum and these are our tubes actually the tubule ones these are used in things like lipid and carbohydrate synthesis so we can make lots and lots of these and another really important role is calcium ion storage big time so very important we'll see that when we talk a little bit about muscles and nerves and then there is the part called the rough er and i should mention too this movie are sometimes shown as a little s capital er so sometimes you'll see that for rough er this is a little r capital er here just like that rough er is used in protein synthesis that's its main main role and the reason that it is uh sort of called the rough er is that when you look at it under the microscope here you will see these tiny little bumps and these little bumps are called ribosomes so these little ribosomes and this is where the protein synthesis is basically taking place we're not going to get into the fine structure of that too much but i do want to introduce this idea here again of whenever you see the word some or soma either as a prefix or a suffix it means little body so a lot of things were described as little bodies because they didn't know what they were they would see them under the microscope and they would say well there's these little bodies there we're not sure exactly what they are and here these are made up of a variety of different things primarily rna so when we look at let's say the er here i'm going to draw part of a nuclear membrane something like this okay so this would be the nucleus here like that and so stylistically i'm going to use some different colors for the for this and coming off of this typically what we find is a series of these sort of flattened membranes and again this is kind of exaggerated exaggerating this like that and again stuck on there are all these little ribosomes so we have ribosomes scattered all the way throughout here also so these would be ribosomes stuck on there so this would be an example of the rough er and so this is the rer portion and either attach that or coming off the nuclear membrane it's itself uh and again we'll just do this in a different color here to sort of show how that that works you might actually have a series of tubes these kind of folded tubes of varying shapes and sizes again this is very stylistic here something like that and again no ribosomes right no ribosomes and this would be then an example of the smooth er and again have different kinds of functions some of these can also come right off the the nuclear membrane as well sort of depends on where we have these but again this is the idea here for the the endoplasmic reticulum now one of the things that happens here in this is when we make things like lipids and carbohydrates and proteins they get sent out into little structures we call vesicles so these can pinch off these membranes can pinch off and form these membrane-bound structures this is known as a vesicle and the same thing can happen here for our structure in the smooth er and this might be filled with a variety of different materials whoops so we'll say that there's a bunch of different molecules that are that are in here and these will then migrate they'll migrate in through the cytoplasm here and so a vesicle is nothing more let me just define this as a membrane-bound fluid-filled structure so a membrane-bound fluid-filled structure organelle that's within the the cytoplasm and again it can have all different kinds of of molecules within it as well and so that's what it what it really is so vesicle again membrane-bound fluid-filled vector vesicle i always sort of think of these like little baggies right you can take a a bag and you can put some fluid in it and zip it up and then kind of transfer it from one place to to another and that leads us then to our next organelle that we have and this organelle is called the golgi apparatus sometimes also known as the golgi complex and here we have basically layers of sort of curved stacked membranes and these are built and say that they're built by the fusion of vesicles incoming vesicles so they're arriving here on this and making these different kinds of of layers that we have and so the way this looks here is we're going to have a series of these kind of curved stack layers kind of like a little layer of pancakes in here and so we have vesicles approaching i'm just going to draw one of these types here as they come in actually start forming these little vesicles and what they do then is they start pinching off themselves and forming their own vesicles so they start forming other vesicles so these are also vesicles but what happens here in the meantime is that when this comes in these are kind of rough products what the golgi basically does is to refine those products makes them whatever they're going to be kind of you know kind of finishes them off so to speak uh in terms of what they do and as they do that then they send these vesicles out here now there are two different kinds of vesicles so we'll call these golgi vesicles just to make sure we're talking about these and you'll sometimes see these are called the cis side and the trans side doesn't really matter here these golgi vesicles here are basically two types the first type that we have are called lysosomes so here's that suffix some again little body and although this has a whole variety of different functions it's really fascinating because in fact there's a whole bunch of what we call lysosomal storage diseases that occur there are about 50 of them that have been found so these are genetic diseases that people are born with uh you may have heard of tay sachs disease that's one of the types or fabry things like that neem and pick disease and they have a whole variety of different kinds of functions but one of the things that they they do which is really important is they are involved intra cellular so within the cell digestion so when things come into the cell they can actually break them apart they can actually digest them they have a whole bunch of these digestive enzymes within them and so they'll eat that up as well another function that they have is actually part of of cell signaling so they can send various signals to different parts and cell telling kind of what's going on what kinds of things are being digested and where they need to go to be transported for these different kinds of vesicles so they stay within the cell but then we have these other vesicles and these are called secretory vesicles excuse me uh secretory vesicles and so they're involved in secretion of chemicals out of the cell so they're going to go out of the cell so things like hormones or sweat or tears or any kind of enzymes and stuff like that that are brought outside of the cell that's how this works so this is going to be for what we call exocrine and also endocrine glands so these different kinds of exocrine glands these are again ones that go out these are things like sweat tears and endocrine always refers to hormones so those kinds of things and we'll talk about some examples of those down the line as we as we go along so we'll see what those are okay another very very important uh one of these organelles is called the mitochondria and that's plural so mitochondrion is singular that would be the singular voice of that okay so so mitochondria these are euphemistically called the sort of powerhouse of the cell this is all about energy for the cell so chemical reactions require energy there's no doubt about it and things don't happen spontaneously typically you need to provide some energy and to run things like anything whether it's a car or city or factory or whatever it is you need to supply some energy for it and this is where this mostly comes from so here we're going to look at this process this is known as cellular respiration so when we think about respiration we also think about breathing but this is how cells actually respire and they respire in different ways it's not really breathing for them basically what we're doing here is we are converting sugar into energy and i usually use abbreviation for for energy here for this so this is a really important process every and i mean every living cell undergoes cellular respiration every single one so we call them primary metabolic process because it's fundamental to every single cell and the functioning of every single cell as well for for this so every single cell does that and the sugar that we're converting is actually a thing called glucose and so the basic formula here is that we have glucose and in order to burn it in fact order to burn anything even water paper or whatever requires oxygen so we're going to burn glucose we're going to break it down this is a catabolic reaction for a series of them a catabolic reaction here to form co2 carbon dioxide water and energy now the energy comes actually in two forms one of these here is a chemical energy that chemical energy is called atp we'll talk more about atp later on i always like to think of it atp as a ton of power atp the other part here is heat energy so when you think about it when you're exercising what you're really doing is you're breaking down a lot of glucose you're burning that and you're also going to generate a lot of heat as a byproduct of that so that's another form of energy so we have our heat energy and our chemical energy that occurs in this so we're going to think of the atp here adenosine triphosphate is what it's called as sort of our universal energy molecule so it's a big time energy molecule now there are different forms of energy chemical energy within the cell and heat energy is also really important within the cell but this is what i like to call 20 energy this is big time energy and it can really run big time things right so you need a lot of fuel to run a lot of the stuff that happens in the cell and we mostly rely mostly relying on atp and one of the things that you want to realize is that carbon dioxide is actually a waste product so what we're doing is we're taking good stuff and we're making some garbage out of it that garbage has to be taken care of and it has to be either converted or released from the body so turns out that co2 can be toxic in large amounts so we have to either convert it or get rid of it so when you breathe in you're breathing in oxygen and what are you breathing out carbon dioxide we're getting rid of a lot of excess carbon dioxide in in all of this okay our third basic component that we have here for the cell so we did the plasma membrane cytoplasm and its organelles at least the main organelles that are here and there's other organelles that i'm not going to have you really worry about for this course we'll talk more about that in physiology if you take that and that is the nucleus and again we're not going to really worry too much about about this but of course this is where most genetic information is and of course most of that is in our dna i have to tell you that this isn't the only place that dna is found dna is also found in the mitochondria as well so mitochondria actually have their own dna but that's for another course again so dna is of course where we have on our chromosomes stores genes and alleles that can be read out to provide the various structural and functional components of the cell and metabolic processes and so forth and all of those different kinds of things that that basically take place okay so that's all i'm going to say about about that so let's talk a little bit about then cellular processes and we'll finish up with that and again we're going to keep this fairly simple in terms of understanding this so there are basically three different kinds of processes that occur that are all about transport so we want to think about this in terms of transport transport within the cell between cells into cells outside of cells so there's a lot of thoroughfare uh action going on here uh with regard to these so the first one i'm going to talk about here is called non-carrier mediated transport that's a mouthful non-carrier mediated so what we mean by a carrier is that remember we talked about those transmembrane proteins some of them can actually function as carriers they can carry things from one side of the cell to the other either inside the cell from the outside or from the outside of the cell to the inside so they can go both ways and different ones function in different ways so here these require oops no energy so these require new energy which is good for the cell so we don't need things like atp and other kinds of energy to be able to do this this is sometimes known as a type of what we call passive transport so things are moving passively through here and these are based on what are called concentration gradients so concentration gradients and you can kind of think of these gradients here as kind of like slopes so for example if we have a slope here like that and what we can do then is we can have some kinds of chemicals or molecules that are up here near the top and we'll say here we're going to have basically high concentration so this is a high constant what we call concentration of this and this would move passively downhill in that direction so if we let this molecule move transport either into the cell or outside of the cell you know it would move passively through that it wouldn't require any energy to be able to do that so there are a couple of different kinds of energy that are used here first of all when we look at what's happening at the high concentration part of this here we have what we call potential energy and what we mean by potential energy is there's a potential to do work and so movement of this molecule here is basically doing work and at the very bottom of all this we're going to have our low concentration so it turns out that concentration gradients always move from an area of high concentration to low concentration in other words they move downhill now once they start moving downhill in this direction this is what we call kinetic energy and the word or prefix k-i-n here refers to movement so anything that's kinetic means movement and that's really what we're we're sort of talking about with regard to this so there are a couple of different types of of this here so we can just say types of non-carrier mediated and the first one is what we call diffusion simple diffusion and we just have chemicals in an area of high concentration that move to an area of low concentration the other type that we have here is a special type of diffusion we call osmosis and osmosis is really about movement of water either into the cell or out of the cell and again in this course we're not going to talk too much about that and we're not going to talk too much about diffusion but the idea here is that this is anything but water that's moving in this direction this is all about water moving in that in that direction as well okay so that is non-carrier media now we can contrast that then with carrier-mediated transport carrier mediated transport all right so what we mean by this here is that this first of all requires this is going to require what we call embedded plasma membrane proteins so we need a protein that's actually embedded and it's transmembrane it goes all the way across from the inside of the outside the outside to the inside here and in this case this works against a concentration gradient in other words what we're doing is we're actually moving uphill so let's look at this again here like that okay and again here we would have oh we can use this color code that we have for this so here we have our high concentration here is our low concentration here and in this case the chemical is this way and we have to move it uphill and that's going to require energy so that energy is going to be typically atp that's going to work that way so this we'll say requires energy and so we're moving this this kinetic energy has to go up against the gradient it's going uphill which means that it's going to take a little bit more energy to be able to to do this typically so when that occurs but it turns out only in what we call active transport because we have actually two types here so in active transport energy is required and these sort of kind of work like a pump so if you wanted to get you know a pump to get water out of the well or whatever you've got to supply some energy so active transport here does that and the name active tells you that it's going to be something that requires energy now there's another type though that doesn't require energy but it still works the same direction and this is called facilitated diffusion so facilitate diffusion and again just emphasize the point here we have two different types of carrier mediated types active transport and facilitated diffusion uh for this and turns out here no do it this way energy required and this is kind of a pretty cool fancy way of the way the cell can actually transport things in and out of the cell and it's based on a change and shape of the carrier protein and again you don't have to really understand the process here but fundamentally when we have this molecule bind to this carrier protein it changes shape and can flip it inside or outside and when it does that it can then release it and allow it to go back to the same shape and redo that so carrying media transport requires a plasma membrane protein embedded here but at the same time it may require energy or may not require energy so with this this energy is for active transport and if we say no atp here this is going to be facilitated diffusion right going in the same direction but just using different mechanisms for this okay and finally here we're going to look at our very last type of transport and this is probably saying thank goodness vesicular or bulk transport and again a lot of these different kinds of transport mechanisms are things that we spend a lot more time uh talking about in giving examples of in physiology but here we sort of want to understand the basic process and how this this works okay so here this requires lots of energy and typically that energy is going to be in the form of atp so yeah very very much so so this can move materials inside or outside of the cell so we have basically again two types that occur uh within this and the first type is called endo again meaning within cyto meaning cell bosus that's condition of so basically what endocytosis does is it moves things into the cell in other words into the icf from the ecf that's the way we're going here so again ecf the icf and the opposite of this is what we call exocytosis and this is of course out of the cell so we're going from the icf to the ecf and in fact that's what those secretory vesicles do they move those things out so we'll talk a little bit about this a little bit later on things like phagocytosis and so forth and how it actually involves lysosomes and secretory vesicles and things like that okay so i stopped there and again next time we're going to talk about tissues and how they they sort of work but before we get into that we're actually going to get into a really interesting subject called embryology and then you'll understand the origin of tissues and how cells will work as groups together