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- [Voiceover] Here is an example

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of a typical animal cell.

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Now there's 20 million things

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you can see going on in here but,

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let's start going one by one

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and work our way through.

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First off, the nucleus.

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It's not always found
right at dead center,

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the nucleus always contains DNA.

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DNA is your genetic code.

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It's what directs and instructs the cell

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on what to do.

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It helps make proteins for the body.

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We have our rough endoplasmic reticulum,

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and then we have our three ribosomes.

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So that blue structure,

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that's kind of weaving back and forth

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with the red dots on it,

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those red dots are going to be ribosomes

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on the endoplasmic reticulum.

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It's called the rough
endoplasmic reticulum

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because you have all these little bumps,

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all these ribosomes on it.

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And as you can see,

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lot of protein synthesis here.

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But you also have some free ribosomes

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just kind of floating around.

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There's little tiny spheres.

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Also more protein synthesis.

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As you head out away from the nucleus

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a little further,

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you get to the smooth
endoplasmic reticulum.

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Now this is where you have a lot of

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macromolecule synthesis, besides protein.

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Things like lipids for example, fats.

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So that's your smooth
endoplasmic reticulum.

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Heading even further out,

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the golgi apparatus,

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or it's known as called the golgi body.

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And kind of think of the golgi apparatus

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as a packing station.

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So to pack things up
and then ship them out.

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Within the cell or to other cells.

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A vesicle, or known as
a secretory vesicle.

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These vessels can help to carry things

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anywhere within the cell

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and then potentially release
them out of the cell.

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Mitochondria,

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think of them as the
power house of the cell.

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Mitochondria produce energy.

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Centrioles.

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You can always find these in pairs

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because the centrioles
aid in cell division.

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One cell can become two

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so each centriole helps
to pull half the DNA

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towards itself.

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Now we have two things,

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these peroxisomes and lysosomes.

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So top left, you see the term peroxisome.

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Kind of looks like a green sphere

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with yellow and brown inside.

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It's meant to destroy your internal waste.

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So it gets rid of things

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that the cells are finding toxic.

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While bottom right,

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you can see the green sphere,

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with kind of almost an
orangish red inside.

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Those lysosomes contain digestive enzymes.

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What happens here now is,

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any organelles,

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which are what all these are,

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or any other cell debris,

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is destroyed and removed by the lysosome.

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Cytosol.

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Think of it as jello inside your cell.

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It's a semi fluid jell material.

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Everything's kind of suspended in it.

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So if you've ever made
jello and put fruit parts

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or any other things inside the jello

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and they kind of just stuck in there,

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that's what cytosol's like.

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Plasma membrane.

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That's the external coating,

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or covering of the cell.

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It's what determines the boundary

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from inside to out.

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And the cytoskeleton.

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Cytoskeleton, it's your framework,

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it's what helps provide
the shape a cell is.

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But besides shape,

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it also helps to anchor
all these organelles

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in place.

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So here is a typical animal cell

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with all its various organelles inside.

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Let's go more information
into that nucleus.

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Already mentioned, the
nucleus contains DNA.

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That's your genetic information.

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That's what can control
the cell functionality

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and control production
of things like proteins.

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So if you look at the surface,

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or the structure I should say

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of the nucleus.

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You'll have these nuclear pores

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around the surface.

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What those are are
simply little tiny holes

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that allow information to enter

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or leave the nucleus.

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But when those nuclear
pores are going through

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it's a double layer membrane.

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So it's two layers thick.

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The inside, where all that
information is stored,

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are in chromosomes, chromatin,

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that's your DNA.

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What's coming and going is your RNA.

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RNA can enter the nucleus,

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it can leave the nucleus.

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And then usually in the
very center of the nucleus,

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you have this structure called

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a nucleolus.

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The nucleolus is more densely packed area

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of genetic material.

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It's more of a longer term storage.

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It's not for the day to day activities.

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So the nucleolus, found
inside the nucleus.

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Ribosomes are where you produce proteins.

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It's protein synthesis.

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Remember there are two types of ribosomes.

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You have free ribosomes,

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the ones that are just floating around

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inside the cell,

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and then you have the membrane bound.

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Those are the ones that
are found on the surface

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of the rough endoplasmic reticulum.

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So we have free floating around,

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and then bound,

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the ones that are

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on the rough endoplasmic reticulum

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or the rough ER.

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So the rough ER is part of
the endoplasmic reticulum.

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It has ribosomes at the surface.

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It's used for protein manufacturing.

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But also, protein modification.

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And this rough endoplasmic reticulum

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is typically the first membrane found

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on the outside of the nucleus.

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While the smooth ER,

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or smooth endoplasmic reticulum

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does not have any ribosomes,

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it's typically further
away from the nucleus

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than the rough ER.

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Because it does not have any ribosomes,

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it's primarily used in lipid synthesis.

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Remember, lipids are your fats.

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But even though it does not produce

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or make protein,

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the smooth ER can help
to package the protein.

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Kind of get in this big bundle

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to get ready to ship out.

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But where's the protein going?

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It's heading to the golgi apparatus,

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or called the golgi body.

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It's refining your synthesized product.

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It's packaging and shipping.

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So pretty much, you can
think of the golgi apparatus

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as like a UPS store, or a FedEx store.

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You take your item in,

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they're going to make
sure it's all set to go,

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package it up,

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and then ship it out.

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That's the golgi apparatus.

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Now it can ship to somewhere
else inside the same cell

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or you might be shipping these products

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to different cell completely

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in another part of the body.

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And the way they are shipped off

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are via vesicles.

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A vesicle is simply a
round sphere of membrane.

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So it's this round membranous sphere

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that the inside is packed

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with all these different products.

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So what can actually
happen in these vesicles,

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they're not just used for shipping though,

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they can also use for storage.

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So in this particular
diagram you see here,

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you can see the golgi apparatus in green.

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And that has these
arrows going up and out.

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Well, sometimes it might
form and make a peroxisome.

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Help them get rid of cell waste,

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anything that's formed,

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and eventually, getting all together,

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breaking it down and
releasing it outside the cell.

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Or if you go to a lysosome,

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this one going to the bottom right.

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Lysosomes are filled
with digestive enzymes.

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If somehow you're able to have a bacterium

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enter into your cell,

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one that should not be there,

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well the lysosome might
be able to find it.

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It can find the bacteria,

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it can then release its
digestive enzymes around it,

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breaking it down.

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And then all those
broken down compartments

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of the bacteria

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are released outside the cell.

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By the time they're released,

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it's not a bacteria anymore.

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It's just broken down chemicals

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that once made the bacteria.

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So peroxisomes are all
these different enzymes

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that detoxify, get rid of waste.

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Lysosome, digestive enzymes,

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break down any foreign
particles, like bacteria.

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And then that power plant,

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the power house of the
cell, the mitochondria.

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One of the unique features
of the mitochondria

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is the double membrane system.

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You can see from the picture,

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how the outer membrane
is just for the capsule.

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Think about a capsule
around a pill or something,

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same idea.

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But the inner membrane is kind of special.

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You can see how the inner membrane

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is having all these folds,

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these indents and creases.

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Any thoughts of why or
what those folds are doing?

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Those folds are meant to
increase surface area.

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More surface area means
more chemical reactions.

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More chemical reactions
means more production of ATP.

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ATP is the energy source for the cell.

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So double membrane,

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helping to use oxygen to make ATP.

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But when it uses oxygen, or O2,

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it's gonna produce or give off CO2,

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carbon dioxide.

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Well how do we get rid of CO2?

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We exhale.

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Eventually, from within the cells,

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this CO2 can make into our blood

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and back into our lungs.

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So we can exhale and get rid of it.

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With a main function here, generating ATP.

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Without ATP, our body's
could not function,

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our bodies could not move,

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our bodies can't work.

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It's the energy source
that runs all of our cells.

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And if your thinking,
well I don't eat ATP,

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I eat protein, I eat carbohydrates,

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I eat lipids.

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Sure.

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All those different components,

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all those macromolecules,

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those big molecules,

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when you eat them,

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they're broken down
into smaller molecules.

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It's those smaller molecules,

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especially glucose

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that can go through a chemical process

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to produce ATP.

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Because ATP is what your cells use.

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They cannot use glucose directly.