hi guys so this is part three of the chapter to sell packet all right so we're looking now at how a cell divides all right so cells typically okay under the signaling of the body okay undergo what's called cell division so going from what we called a parent cell to two daughter cells so the cell theory states the following states that the cell is the basic unit of life there's nothing smaller than a cell we can consider living right and then all organisms are composed of one or more cells okay so if you're considered an organism you have to have at least one cell now adding to this okay we also saw let say that cells come from pre-existing cells okay and how is that possible well again it happens via the process called cellular division all right so the premise here if we go to our white board again is we're gonna take okay what's called a parent cell okay so here's our original cell okay here's our nucleus and we're calling this a parent cell and via the process of cellular division hey we're gonna produce two daughter cells okay so I'll just put DC for daughters also there's a daughter cell and there is a daughter cell so let me ask you a question alright are the two daughter cells identical to one another yes or no okay and the answer is yes all right so this daughter cell is identical to that daughter saw all right second question are the two daughter cells identical to the original parent cell from which they came from the answer is yes okay so this process of cell division okay let's get specific involving mitosis okay and something called cytokinesis okay it doesn't change anything okay all it really does it goes from having one cell now to two cells all right and we call this process against cell division all right now so if I were to ask you guys what's reproduction okay you may say having kids right having offspring well which is true right when you when you reproduce you have kids now we're going to talk about reproduction but not at the organismal level we're gonna talk about reproduction at the level of the cell the cellular level okay and occurs much more often at the cellular level than it does for example right at the organismal level so for example we again begin at the point of conception we began our life as a single cell called a zygote okay and through the process of cell division okay mitosis and cytokinesis that one Zygo became the 100 trillion cells that are present in your body today alright so in just one second right millions of your cells just divided in two okay so parents all divided to form two daughter cells so here's what we showed you at the very beginning of chapter two okay this one's I goat gave rise to the 100 trillion cells that ultimately came allowed you to produce okay all the different parts of your body okay so besides development besides going from a zygote to an embryo to a fetus to a baby to a toddler to a grade schooler right to a junior high to a high college student and so forth and so on okay what else - cell division - for us well it also plays a role right in the replacement of lost and damaged cells all right so if you sit down on the Sun too long and you get a sunburn well how do you then replace those cells okay that were lost because you were sitting out in the Sun too long that UV light fried and killed those cells yeah or if you fall off get your skateboard and you scrape your arm right and you lose cells how do you replace those cells so via that same cell division okay via mitosis cytokinesis we replace lost and down ourselves at the same time okay if I compare the amount of cells in a newborn baby to the amount of cells in a high school okay a person or a someone in college okay the person that is a lot bigger right has a lot more cells so how did that happen well that also happened via cell division via mitosis and cytokinesis all right some other organisms they have the ability to regenerate lost body parts so here's a sea star okay and you see it ain't growing this long appendage here okay if you cut the tail off a lizard what can possibly happen well that lizard can grow its tail back okay so some organisms have the ability to grow right new parts now before a parent cell divides what does it have to do well it has to duplicate all of its genetic material right so we talked about in part two okay of chapter two okay the idea that matching pairs of chromosomes are called homologous chromosomes let's say this is chromosome one that you got from your dad this is chromosome one that you got from your mom okay we call these homologous homo means same right now we know these are similar to one another but they're not identical okay homologous chromosomes are similar but they're not identical okay so before a parent cell divides it has to duplicate all of material for example chromosome 1 from dad it has to replicate from Osan 1 for Mom it has to replicate right and the reason for that is what well if I go back to that original drawing that I drew here right and let's make this nucleus a little bit bigger second I can draw something inside of it right and let's say okay there are 46 chromosomes in this parent cell right and let's say we do not have a replication of the DNA before cell division okay so let's say we do not replicate our DNA so all I have to work with is 46 chromosomes well to be fair then to the daughter cells okay I'm gonna give half the chromosomes to one daughter cell 23 okay I'll give them the other half to the other daughter cell all right so let's ask those same questions again are the two daughter cells identical to the original parents on though when the answer is no right the parent cell has 46 and now the daughter cells only have 23 each right well let's ask the second question are the two daughter cells identical to one another yes or no well the answer is no right so I made the analogy right homologous chromosomes are similar but they're not identical they're like the pair of shoes that you have on your feet okay or let's say this is chromosome one that you got from your dad okay and this is chromosome one that you got from your mom okay and let's say I give this chromosome one to this daughter cell I give this chromosome one okay to that daughter so so it's like giving I gave this one the right shoe and I gave them one that the left shoe right so even though they're the same color where and they're the same style of shoe well this one's the right shoe and that's the left shoe so even if I did give copy of chromosome one to that and copy chromosome one to this okay they're not identical all right the number of chromosomes is the same but the actual chromosomes themselves they're not identical so there's an issue guys okay of not replicating your chromosomes before cell division you have to replicate your chromosomes before cell division right so if you replicate your chromosomes before cell division now hey what happens here well I'm just erase all this makes it a little easier well here's the daughter cell okay and here's the other daughter song and let's say before cell division I brought the keys chromosome okay so i replicate - chromosome one okay i replicate mom's chromosome one right so these are still considered homologous chromosomes they've just replicated one another right so if I ask you what are these called still these are still called homologous chromosomes okay so what do I call these though okay this chromosome one from dad that replicated well you call these sister chromatids okay what do I call these ones okay that replicated one same deal you call those sister chromatids also okay so we know the homologous chromosomes are not identical they're similar what about sister chromatids when i replicate - chromosome one are these identical copies of - mom's ones are these sister chromatids identical the answer is yes so when you make a copy you make an identical copy right same deal what about these sister chromatids mom's chromosome one okay are these sister chromatids identical the answer is yes right so when I make a copy of mom's chromo someone you make an identical copy okay so by replicating your chromosomes before cell division very important before mitosis and cytokinesis what can happen now well since I have two copies of dads chromosome one well I can give one to each okay cell I can give a copy of dads chromosome one to this daughter cell and it can give a copy of dads chromosome one to that daughter cell okay because I have two of them I've replicated them same thing with moms chromosome one because I replicated them I can give a copy of moms chromosome one to one daughter cell and a copy of moms chromosome one to the other daughter cell okay so are these daughter cells identical to one another yes they are are they written identical to the original parent cell before we have replicated a case remember okay what did this look like before we replicated we only had one copy of chromosome one from dad we only had one copy of chromosome one from mom right so our daughter cells identical yes are they identical original parents though yes so very important before you divide a parent cell okay you must rub the kth genetic material okay so here are unreplicated these are homologous chromosomes okay here are replicated to Monaco Muslims again individually we call these sister chromatids we call these sister chromatids okay so question to you okay how many cells do you end up with when a parent cell divides okay so two cells three cells right so if this parent cell divides different to mark two daughter cells how many cells overall do you end up with half your cell division you end up with two right because the theoretically what happens this parent cell divides to form this cell and that cell okay so we formed two daughter cells we go from one to two so idea of mitosis is we're not changing anything okay we're not changing okay the number of chromosomes were simply increasing the number we're going from one cell to two cells okay and if these two cells were to divide what happens well now you have four cells okay if for those four cells were to go with cell division well then you have eight and then you have sixteen and so forth and so on all right so we're not change anything when we do cell division involving mitosis Ida Kinesis all we're doing is increasing the number of cells all right so next question to you guys is what is a genome right the Gangstar gnome on somebody's lawn well a genome is a what well it's a complete set of an organism's genes right and these genes are located on a chromosome so let's define what a gene is okay genes are sequences of nucleotides sequences of DNA the a's the t's the c's and g's that we talked about in part two okay of this packet okay so it's the sequence of a's t sees and cheese that code for what that code for a protein or a functional RNA genes are sequences of nucleotides sequences of DNA that code for a protein or a functional RNA okay and these genes are located where these genes are located on chromosomes all right located on your DNA so if genes are located on DNA all right are they located on chromatin yes well if genes are located on chromatin are they located on super coiled DNA just just tightly packed okay now she gave was a hardwired telephone and the cord is wrapped on itself right well yeah well jeans are on super coiled DNA our genes on chromosomes well the answer is yes okay so because genes are on DNA genes are on chromosomes all right genes again seeing this is a DNA sequences of a's t CS and G's that code for a protein or a functional RNA alright so chromosomes again are the highest order and level of packing right highest order and level of packing okay you don't see chromosomes unless what unless is the cell is dividing okay so unless excels undergoing mitosis Alessa cell is undergoing meiosis which we'll talk about later on right now review chromosome structure okay so let's go to our pseudo white board again when I think of a chromosome a chip eclis see something that looks like this right so here you see something looks like this where we call these parts okay right in the middle okay well sometimes not in the middle you might see a chromosome where you see it look like this possibly right but this constriction that I see right we call that a central here okay that is known as a centromere the ends of a chromosome okay and I'll just highlight them for example this end right here or that end right there okay we call the ends of a chromosome we call these telomeres okay so you have a centromere at the middle or not sometimes always a middle but the constriction okay and you have the ends of a chromosome we call those telomeres okay so here's a karyotype again okay here we're showing you right 46 total chromosomes 23 pairs okay we're 22 of the pairs we call autosomes again right and then the last pair the 23rd pair we call these sex chromosomes okay so here's the karyotype of a female we see that this individual is X X now before a cell divides again okay you must replicate the DNA so here's just one chromosome okay we're not showing you how Malgus pair okay and when it replicates we connect at the centromere right and here we see two sister chromatids and again our sister chromatids identical so when this chromosome replicates you create identical copies okay all right so what we're gonna talk about right now okay is this process of how a cell divides okay so when the cell is not dividing it is not in something we call the cell cycle all right so in a non dividing cell okay cells are in a part that's outside the cell cycle okay we call it g0 okay or G not okay so this is a non dividing cell right here now when a cell is told to divide okay it's gonna exit this g0 okay and it's gonna enter the cell cycle okay and the first part of the cell cycle okay it's called the g1 the growth one or the gap one phase okay so the first part of cell cycle okay we're gonna divide we're gonna go for my parents out to two daughter cells we need to get bigger okay so we're gonna grow okay so we exit G naught okay we're gonna divide so we grow the first part of the cell cycle is g1 okay after that we need to replicate your genetic material okay prior to cell division we call this s face okay so this is where DNA replication occurs in the cell cycle right and then after s phase we grow even more okay we enter what's called G - the growth - or the gap to face right so g1 s g2 right we call this interface all right we grow we replicate our DNA can interface makes up 90% of the cell cycle right we're now to do what we're ready to do cell division we're ready to undergo mitosis and cytokinesis right and there's different parts of mitosis cytokinesis okay mitosis okay we have what's called prophase I'll just put a pea here first gain after prophase you enter something called metaphase after metaphase you enter something called Anna face after anaphase you enter something called telophase okay and that's mitosis and the very last part here a division of the cytoplasm I'm gonna overlap it with telophase we call this cytokinesis alright and actually put on the other side because I need to draw here okay so overlapping telophase we have something called cytokinesis so this part here we call this the mitotic phase of the cell cycle and the mitotic phase makes up 10% of your cell cycle so leading up to cell division you have interphase 90 % g1 s g2 okay and then the mitotic phase yeah prophase metaphase anaphase telophase where you divide the nucleus and then you overlap that with the division cytoplasm called cytokinesis right so here on this slide okay you can see that okay what's not shown is G not okay so if it sells not dividing it is not in the cell cycle it's out here right but let's say the cell says okay the body says oh you're getting a little old okay let's divide in let's go from a parent cell let's get some two brand-new daughter cells so we have the g1 phase okay the gap one growth from face and we get larger we grow we're about to divide okay we then entered s face okay so this again case where we replicate our DNA okay and then from there we grow even more we enter g2 gap to phase grow to phase right and then we enter cell division we enter the mitotic phase so prophase metaphase anaphase telophase okay you then have cytokinesis okay so you can divide it again you can go second round of cell division or you can exit the cell cycle possibly all right so interface makes up 90% of cell cycle mitotic phase makes up 10% of the cell cycle all right so let's talk about mitosis what is mitosis mitosis is the division of the chromosomes okay so again it's preceded by interphase okay it's preceded by g1 s and g2 so by the time we enter mitosis we've already replicated our DNA okay so mitosis if you look on this figure consists of four different phases okay right after g2 you prophase okay then you have metaphase okay then you have anaphase and then you have telophase okay once telophase is done mitosis is complete okay now cell division isn't done why because you still have to divide the cytoplasm gate you have cytokinesis okay so the misconception is that mitosis is not done until after cytokinesis okay yes the mitotic phase is not done but mitosis is done okay prophase metaphase anaphase telophase is mitosis the second telophase is done mitosis is done okay cell divisions not done because we still have to then divide the cytoplasm inside o Kinesis all right so these slides here guys okay go ahead and review them prophase metaphase anaphase telophase okay what we're gonna do right is we're gonna then trawl these things as opposed to just you know reading off the slide and showing you what's already there okay let's actually draw these things on our pseudo whiteboard here all right so let's say here is our okay cell all right so this is our parents out here all right and there you go and there's the nucleus now before this okay I'm gonna draw a key over here all right to kind of show you things and we're gonna show you two homologous pairs right and we're gonna actually show these things in two different forms okay we're gonna show the the DNA in the form of chromatin okay we're also gonna show the genetic information in the form of chromosomes all right so if I draw something that is blue okay and squiggly line okay and if I just if I mark it in this would be chromosome one okay that you got from your dad okay in the form of chromatin okay if I don't shade it in okay it's number one that you got from your mom all right now we're also gonna show you a second homologous pair okay so here's chromatin all right okay this will be note numbered okay two for that you got from dad okay and if I sorry if I shade it in I'm sorry if I'm marketing if I don't mark it in okay this will be two that you got from your mom all right so that's what that's how I'm trying to represent it in form of chromatin okay so when the cells not dividing again we find chromatin when the cell divides well now you have chromosomes right so here's it's gonna be one from dad okay in the form of chromosomes okay here's gonna be one for Mom in the form of a chromosome alright so this is gonna be two from dad in the form of chromosome okay and this is gonna be two for Mom again not shaded in in the form of chromosomes alright so again we call these homologous chromosomes okay these would be homologous chromosomes these are chromosome ones these are chromosome twos right now when they replicate okay if you were to have DNA replication okay what would these chromosomes look like okay because again replication occurs here prior to mitosis right during S phase of interphase so one from dad is gonna look like this connected at the centromere okay these would be sister chromatids okay - to me one for Mom will look like this connected at their centromeres right so these again they're still considered homologous chromosomes okay these are still considered homologous chromosomes okay so there's similar to one another okay but they're not identical all right these here are called sister chromatids okay so when I make a copy I make sure I make an identical copy okay same thing with this one these are sister chromatids right now in terms of these homologous chromosomes okay I'm not gonna label them but here's dads chromosome to replicated okay and here's mom's chromosome to replicated all right so there's our key right device make a squiggly lines chromatin okay if I make them look like this these are chromosomes and if they replicated they'll look like that okay so there's no key there okay so this is a parent cell it's not dividing it should I put chromosomes in here or should have put a chromatin in here well if they're not dividing I should put chromatin right so here's gonna be one from dad here's gonna be one from mom okay here's two from dad okay and here's two for Mom okay so I'm just drawing two homologous pairs right I'm not drawing a chromosome three chromosome four comes from five from some six okay I'm not drawing the sex chromosomes okay so what I'm drawing is a simplified explanation okay but in reality there's a lot more chromosomes involved all right so here's chromatin all right chromosome one and two in the form of chromatin and then what well prior to cell division okay during S phase of interphase we need DNA replication okay so we're gonna replicate our DNA okay when during S phase so what we see here now right here is that same parent cell okay the only difference now though is we're gonna replicate every single part okay so one from dad is gonna replicate one from mom replicates right two from dad replicates two for Mom replicates okay so the DNA replicates hey then we go to g1 now we're ready to enter mitosis alright so we're gonna take this cell here right and we're gonna enter in mitosis okay so the first part of mitosis is what well the first part of mitosis is something called prophase okay well prophase so here's my cell okay here's my nuclear envelope it's gonna make it bigger so I have a bigger space to draw alright and what happens in prophase well one thing that happens is that the chromatin condenses to form chromosomes okay so instead of looking like this - chromosome one now it looks like that okay so we go from being chromatin ten our chromosomes instead of looking like this mom's chromosome one now looks like this okay so chromatin condenses to form chromosomes same thing with dads - okay we start to see something that looks like this shade it in okay and here's mom's - not shaded in okay so one thing that happens in prophase chromatin condenses to form chromosomes alright another thing that happens right is that their nuclear envelope disintegrates okay so this envelope that separated the nucleus from the rest of the cytoplasm okay this nuclear envelope disappears okay so now the chromosomes are mixed in with everything else inside of ourselves okay all right so chromatin condenses from chromosomes nuclear envelope disintegrates all right now nothing that happens is that mitotic spindles from the central zones memory centrosomes guys with the centrioles okay they begin to extend their microtubules all right so that's the centrosome that's the centrosome they extend their microtubules and they begin to grow okay and they grow and they actually push the centrosomes to opposite poles of the cell all right so they started off really close to one another okay the microtubules attached to each other okay and as they grow right they push the centrosomes to opposite poles of the cell and then last but not least okay mitotic spindles from each centrosome attached to your chromosomes okay so recapping prophase okay chromatin condenses to form chromosomes nuclear envelope disintegrates okay mitotic spindles okay extend and attach to one another okay pushing them the centrosomes to opposite poles of the cell and then mitotic spindles attached to our chromosomes okay so that's prophase the next part of mitosis okay is metaphase okay so what happens in metaphase well something's gonna line up along the middle alright so let me draw it down here I'm gonna stagger it so I have okay Pitt places to draw basically okay I can make this cells bigger if I if I stagger them okay so the middle is something we call the metaphase plate pleat okay metaphase plate okay and so what lines up along the metaphase plate is the question well answer that question there are sister chromatids okay so lining up on the metaphase plate are sister chromatids so here's dad's chromosome one okay we're gonna draw it like this okay so one sister chromatid is on one side of the metaphase plate the other sister chromatid is on the other side of the metaphase plate okay mom's chromosome one okay one sister chromatid is on one side of the metaphase plate the other one is in the opposite side on the metaphase plate okay dad's chromosome two okay on one side of the metaphase plate one sister chromatid okay mom's chromosome two okay sister chromatids line up again along the metaphase plate okay so what actually maneuvers what maneuvers these chromosomes to that metaphase plate well these mitotic spindles okay the mitotic spindles from opposite centrosomes okay lying the sister chromosomes some sister chromatids up along that metaphase plate there okay so recap what happens in metaphase sister chromatids line up along the metaphase plate okay sister chromatids all right the next part now is something called anaphase okay anaphase right after metaphase is what's gonna happen here okay so what does this look like about to happen okay it looks like there's about to be a tug-of-war right now a couple things happen before I do the tug-of-war okay so this mitotic spindle here and here okay and here and here the ones that are attached from opposite centrosomes these ones get longer and they push the centrosomes to opposite sides okay at the same time okay by growing longer they're gonna now cause the cell to stretch instead of being smear achill okay our cell becomes kind of oval or oblong okay and the reason why again is because that mitotic spindles from opposite centrosomes that are attached to one another okay these okay push apart from one another they stretch our cell okay whereas these ones here okay that are attached to our sister chromatids okay these ones here will get shorter in length okay and when they get shorter in length what's gonna happen well they're gonna pull the sister chromatids apart from one another alright so these mitotic spindles okay will get shorter in length okay causing them the separation of sister chromatids so here these get shorter so we pull apart dads chromosome one okay so one sister chromatid goes this way the other sister chromatid goes that way okay we separate mom's chromosome one okay so sit one sister chromatid it goes to one side of the cell the other sister chromatid goes to the opposite side this off okay same thing with dads too okay sister chromatids separate okay same thing with moms two sister chromatids separate so what happens in anaphase one is what okay sister chromatids separate okay so we separate our sister chromatids and then the last part of mitosis right it's called telophase okay so telophase is basically opposite of prophase okay so what happened in prophase well chromosomes okay condensed okay from chromatin to chromosomes nuclear envelope disintegrated okay and then all these mitotic spindles extended well the opposite of that is what well mitotic spindles are gonna retract so here's my cell now okay so instead of having these long mitotic spindles they retract okay so there's one central zone there's another central zone okay what's another thing that happens well nuclear envelope reforms it disintegrated in prophase well now my nuclear envelope is going to reform in telophase okay what else well chromosomes okay condensed from chromatin well the opposite of that is that chromosomes wildy condense to form chromatin so instead of looking like this okay chromosome one from dad is gonna look like that okay instead of looking like these okay chromosome one from mom's gonna look like this instead of looking like these well then chromosome two from dad is gonna look like this okay instead of looking like these will then chromosome two for Mom it's gonna look like that okay so chromosomes D condensed to form chromatin in telophase right and the telophase done yeah it's done so as mitosis done yes because mitosis is simply prophase metaphase anaphase telophase okay is the mitotic phase done is cell division done no it's not alright mitosis is done but the mitotic phase of the cell division of the cell cycle okay and cell division is not done yet we still have to do cytokinesis right an overlapping telophase you have something called cytokinesis okay so the telltale sign that cytokinesis is occurring in it in overlaps telophase okay is you form something called a cleavage furrow right where you start to invaginate the plasma membrane okay so instead of looking spherical like that we start to see this invagination of the plasma member like this okay and that structure that's formed okay and goes 360 all the way around right we call this a cleavage furrow okay now ultimately that cleavage furrow is gonna meet at the middle okay and when you do that what happens well then you then separate the two cells from one another okay you separate the cytoplasm okay of each daughter cell okay so let me try to separate these out into two individual cells it's gonna be kind of close because the nuclei are really close to one another so here's one daughter cell now okay here now is a second daughter cell okay so this is one daughter cell okay this is the other daughter so the daughter cell is identical to one another yep one striped one night strike one strike one not striped okay are they identical the original parent cell yeah right two blues two greens striped not strike strike not strike two blues two greens one striped one not strike one strike okay they're identical so what did we do in mitosis we went from having one cell to two cells okay so we increase the number of cells gate using mitosis alright so hopefully that helped guys okay as opposed to me for example going here and reading okay but prophase is and what metaphase is and what anaphase is and what telophase is okay so let's pick up here right after telophase is mitosis complete yes mitosis is complete is cell division done yet no okay we have one more step and that step again is called cytokinesis the division of the cytoplasm alright so here you can see a scanning electron microscopic image of a cleavage furrow forming between the two daughter cells okay so that cleavage furrow goes in eventually then separate in form to individual daughter cells there all right so this next part can in this last part of our packet okay we're gonna talk about cancer okay so that may be an extreme jump right going from cell division to cancer but in actuality it is not right cancer is basically uncontrolled cell division right so when your cells divide it's a very highly coordinated process okay it's very regulated also okay cells just can't decide on their own that they want to divide your body has to signal them to divide right now there's some rogue cells out there okay that don't listen to the body okay they don't wait for the body to give them a signal to divide they just divide on their own okay at the same time their body is telling them long you need to stop okay but they're not stopping they just keep dividing so here if we see a cell cycle okay we actually see the gene not the g0 if a cell's not dividing right but then we see well if I divide then enter the cell cycle so the first part of interphase is g1 okay where I grow the next part of the interphase is s phase where I replicate my DNA okay the next and last part of interphase is g2 where I grow even more okay and then I enter mitosis and cytokinesis then I divide right now add it to this picture of the cell cycle we added these red arrows okay what are these red arrows represent they represent checkpoints okay your body monitors the process of division and it says well yes you did g1 but did you do did you do g1 properly if you did it properly I'll let you go into s but if you didn't need you to stop right now and you gotta fix the mistake that you made okay and if you don't fix the mistake you made I'm not gonna let you keep going okay so there's a checkpoint there's a quality control basically oh you did g1 good bye go ahead go into s face let's replicate your DNA okay but there's also check points in DNA replication when I copy the DNA you make an identical copy sister chromatid should be identical to one another and if you make a mistake boy you got to go back and fix it you can't fix it well that I'm not gonna let you go anymore okay well let's say you did it perfectly fine well then you can go into g2 na and there's another checkpoint and then even in mitosis there's more checkpoints so by having the checkpoints your body is making sure that that those daughter cells that are produced are identical to the two daughters up to the original parent cell okay it's making sure no mistakes occur this is a very high level of quality control here all right so what do you think cancer is cancer ourselves that have uncontrolled cell division so what do you think they do to the checkpoints okay they bypass these checkpoints all right they just divide and divide and divide and divide so cells can reproduce at the wrong time place you can form tumors right benign tumors are harmless tumors malignant tumors are the one you need to worry about all right so cancer okay is a class of disease in which a group of cells display the following characteristics number one uncontrolled growth okay division upon normal limits all right invasion they start to invade a Dacian adjacent tissues and cells so imagine guys if you're in your room right now okay studying okay and it you have the room all to yourself and all of a sudden okay I say to you well here your new roommates all right here's five people that I'm gonna put in your room okay and you have to do your normal thing you need a study you gotta okay do everything that you normally do okay that's probably not gonna work very well so when when cancer cells start to invade adjacent tissues what do you think happens to those adjacent tissues well they start to now malfunction they're not gonna function properly anymore okay and sometimes you never want to hear this okay the cancer spreads okay is it there's an original spot where started but because you have blood vessels okay because you have lymphatic vessels well those cancers spread cancer cells can go from one part of your body to another part your body we call that metastasis all right so cancer is caused by the breakdown in the control of the cell cycle okay cancer cells ignore these cell checkpoints so here guys you can see right a common type of cancer breast cancer all right so I'm gonna ask you guys to imagine this first okay here I'm showing you three panels of breasts okay imagine there's another one over here okay that just has one red dot in it okay just a single cancer cell and prior to that another breast that has no red dots okay so I'm asking you imagine okay one breast that has no cancer one breast that just has a single candidate to cancer cells just a single red dot okay so what happens okay is that a cancer cell arises you go from okay a breast that is cancer-free to now a breast that has just one single cancer cell right do you think the woman's going to sense having that one single cancer cell okay the answer is no you're gonna feel perfectly healthy perfectly fine okay but through the process of cell division that one cancer cell becomes two cancer cells becomes four cancer cells becomes eight cancer cells become sixteen cancer cells 32 64 128 256 of iDevice eventually you form a mass of cancer cells you form what's called a tumor okay do you think the woman's gonna be able to sense this now okay anything different yeah okay so you feel a lump in your breast right let's do two scenarios scenario one okay you know your body very well that that lump wasn't there before so you go to your doctor can you tell your doctor I feel this lump that wasn't there before all right so your doctor does a biopsy takes a sample of it and the surrounding tissue okay sends it to the lab okay and it comes back as a malignant tumor all right your doctor says well it's very good that you came in because this is a very okay aggressive cancer okay what we can do is we can now remove this tumor we can remove the surrounding tissues just to make sure there's no strays there okay we can put you under chemotherapy we can irradiated okay and then after weeks of treatment you keep going back for testing more testing okay the cancer is gone okay so congratulations you are a cancer survivor you caught the cancer early okay scenario two right you felt the tumor in your breast but you don't do anything about it like eyes just like a swollen lymph node or something all right so you just go on your day and go on your weeks your months your years okay and what happens okay it grows it gets bigger it starts to invade other tissues so this yellow stuff here this is glandular tissue this is the tissue that makes okay milk okay when a newborn baby suckles at the nipple so do you think this glandular tissue now is gonna function properly II think it's gonna produce milk and the answer is no okay so now we have the spreading of cancer in the breast right you see that actually no one ever knows there's a lump right there right so this probably is more painful now okay so scenario one okay you say to yourself well now I'm gonna go to the doctor okay the doctor does the biopsy the lab work comes back says yeah this is a milling the tumor okay the bad news is spread already in your breast so instead of just removing the tumor okay and the surrounding tissues we have to remove the entire breast now okay so you go back for testing okay chemotherapy or radiation okay neck comes back negative every time okay congratulations you are a cancer survivor all right scenario two you still don't go to the doctor okay so the cells divide divide divide divide be the cancer gets even bigger now okay now this stuff right here these are lymph nodes and not lymph nodes but lymph vessels okay these ones ultimately will reach your blood okay they carry an excess tissue fluid called lymph back to your blood right so now what happens is that these cancer cells they enter the lymphatic vessels and each one of these red dots here represents a single cancer cell right and those single cancer cells reach your blood where does your blood go your blood goes everywhere so now one of these red dots ends up in your pancreas okay and the same thing happens now you have tumors in your pancreas and now you have pancreatic cancer one of these lands in your liver now you have liver cancer one of these lands on your brain now you have brain cancer right so now the cancer isn't localized anymore the cancer has metastasized it's now spread to different parts of your body okay so that's that's the thing about catching cancer early if you can catch it early enough okay it's very possible right it's not gonna metastasize and you're gonna survive from it all right okay so how do you treat it right well at that point okay if it metastasized we're talking about just global chemotherapy now okay and chemotherapy drugs they're basically poisoned right and what are these drugs do okay this is typically how it is they're set up okay with an IV they involve drugs that disrupt cell division okay so you're looking to prevent this from happening this this growing of the tumor basically all right the thing is though okay do these same drugs target normal cells that are not cancerous that need to divide right for example your hair needs to your cells in your hair need to divide so that your hair grows so what happens when people have chemotherapy well the hair falls out because you don't have cell division all right so that's how we will treat it okay in some cases right now cancer cells can cancer is a disease we haven't we haven't figured out yet all right there's no cure for it one of my dreams is why don't win it one of my students that I've been teaching over the years Kay decides well maybe Nursing is not for them maybe I'm going to become a doctor maybe I'm gonna become okay a research scientist with a PhD right and you find a cure for cancer hey that's my like my ultimate goal that one of my student escape figures it out okay now you're gonna get the Nobel Prize alright get a million bucks and I don't need any of that money okay all I want is a shout-out right yeah I was really interested in stuff because I took his class at Rio Hondo okay his name was dr. bio alright just got me so pumped up about this stuff I want to find the cure for cancer and I did alright so here we see a scientist growing okay cancer cells okay in culture for study all right so what are some prevention ok possible prevention well okay there's there's chemicals out there guys you you don't have to put in your body okay so smoking right there's lots of carcinogens these are cancer-causing agents okay and lung cancer is not the way to go guys right okay the Sun has UV light okay so avoiding overexposure to the Sun okay you you do want exposed to get supposed to Sun because Sun has been UV light is beneficial okay a dosti allows you to produce vitamin D and vitamin D is needed to uptake calcium from your diet for healthy and strong bones for example but too much Sun can be a bad thing why because UV light okay is a very low wavelength very ionizing radiation can mutate your DNA can cause skin cancer okay eating a high-fiber low-fat diet why colon cancer okay getting physicals every year okay just making sure everything's good okay if you don't want okay okay someone else to do an examination on you okay you want to just do it I know perform self examinations everything sound youtube self breast examination and self testicular examination okay testicular cancer is a young man's cancer right and then there's different websites you can good everything is on the Internet right at this last part here I wouldn't stress over too much guys we're just basically showing you right we gave you a pimped-out cell a generalized cell that had all the different organelles the plasma membrane a nucleus okay but again there's different cell types there's 210 different kinds of cells that make up the 100 trillion okay so here's just a snapshot of the different kinds of cells that we're gonna experience over ok the next couple of weeks all right so here we have a fibroblast okay these are cells we find and connect the tissue proper right they make these fibers present connective tissue here is in the wreath Row site here's a red blood cell okay there's no nucleus and it's not spherical its rate is basically flat okay it's a biconcave cell okay why does it biconcave because it gives it 30% more surface area compared to a cell that is shaped like a sphere okay what do I need surface area if I'm a red blood cell because you have gas exchange right you pick up oxygen you drop off oxygen you pick up oxygen you drop off oxygen so if you have more surface area you have more interaction with the surrounding environment okay so here's an epithelial cell why does it have multiple sides because I need to connect to other cells to form a sheet of cells right so lining your stomach lining your skin right you find epithelial cells a nice continuous sheet why I need multiple sides so I can connect to multiple cells all right then we see these cells that are very long right this is one cell guys it doesn't look like a ball to me it looks like a rod right well these are skeletal muscle cells all right there are so long we actually call them skeletal muscle fibers why'd it have to be so long because when they get smaller when they contract okay they generate a pulling force causing something to move right and then we have a fat cell with an inclusion called a lipid droplet right so what are these do will they store fat and then we have these cells that have pseudo pods why well because these going around okay looking for things the phagocytose we call these macrophages so what's the main purpose of this well because structure determines function right why does a neuron look like this because it has sent info from one part of your body to another part of your body that's why has these long process but that's why it has his packs on here okay and then we have the Oh site the largest cell in the unibody right and then we have the only motile cell you embody this for himself why does it have a flagella because it has to swim to the female reproductive system to fertilize the egg within the fallopian tubes alright and this last slide they're just theories right so we know that we all began our life as a single cell okay when the sperm fries the egg called the zygote and through the process of cell division okay we made the hundred different hundred trillion cells that are present in your body today right so what about aging well there's different theories behind aging right one is a free radical theory we talked about this right free radicals have unpaired electrons in their outer valence shell what do they do they were highly reactive they want to pair those electrons okay so these are just the byproducts of this normal chemical reactions in your body so that the theory is well the longer you have lived the more metabolism you've done in your lifetime the more free radicals you've produced well if the more free radicals we'll take the react now they can mess up your DNA they can mess up your your cell membranes they can mess up your proteins well that then leads to things going wrong and that's why you start to break down as you get older all right another theory of aging is the mitochondrial theory meaning what well you produce less ATP well the less energy you have well then you have a weakening and aging of ourselves alright and then you have a genetic theory right the telomeres are where well those are the ends of the chromosomes okay every time you do DNA replication the ends of your chromosomes get shorter and shorter and shorter every time you do a round of cell division every time you replicate your DNA okay but to the rescue is an enzyme called telomerase these do what well these then lengthen your telomeres again alright so the theory is that right let me just kind of draw this here that's the very last thing on their very last slide you're right cool hey can we end this lecture ready here is a chromosome okay and then the ends of the chromosome again these are the telomeres okay so here's the telling we're here here's a telomere over here okay so during DNA replication what happens right is that you start to now shorten your chromosomes okay we lose that much of a telomere and we lose this much of a telomere okay now the thing is though telomeres don't have any okay vile information they're just repetitive sequences but as we get into the inner parts of the chromosome no these are where the genes are located okay so the theory is well the older you are okay the more DNA replication you've had well then you start to eat away at these telomeres okay the problem arises now when you start to eat into the part that has the genes now okay stuff starts to go bad there so what does telomerase do well telomerase prevents the shortening of the chromosomes telomerase adds to telomeres back all right so there's an enzyme in your body whose job is to now prevent the shortening of your chromosomes and that enzyme is called telomerase all right so that ladies and gentlemen okay is the very end of this very long packet all right this is part three all right so hopefully you got your studying well hopefully thing everything is going right in this online environment okay and again if you have any questions just please email me within the canvas shell all right so I'll see you guys on the next lecture but