Okay. Let’s talk about partitioning
and why we want to have
within the cell.
So, cell membrane and other
membranes within the cell.
Let’s first start by talking
about the cell membrane
because this is probably
the most important because
it separates inside the
cell from outside the cell.
And why this is so important is
if we talked about homeostasis
and maintaining the internal
environment within the cell,
we need to have some sort of
separation mechanism to keep tha
inside and separate
that from outside.
However, each portion of
the cell or its organelles
will have various membranes
associated with them.
reticulum is one,
and in this endoplasmic reticulum,
which could be rough or smooth,
is oftentimes where protein
synthesis is taking place.
This is also where you could be packaging
some of the cell secretions that may occur.
The Golgi complex is kind of an
extension of the endoplasmic reticulum,
where further processing takes place and
eventually, you’ll get some budding
of various vesicles and that will be
what our secretion mechanisms will be.
We also have various smaller cellular
structures, such as lysosomes and peroxisomes.
These are located close to the
cell membrane, just on the inside.
And these will be involved with breaking
down either via enzymes and lysosomes
or via reaction oxygen
species with peroxisomes.
Proteosomes are also break
down vesicle structures,
but these involve a process in
which you ubiquitinate a structure
and then it will be trafficked to that
proteosome for destruction or break down.
Luckily, we recycle many
of those products that
get broken down and the
cell will use them again.
The mitochondrial membrane
is the final kind of
organelle structure membrane
that we’ll talk about.
It’s a little bit more specialized, in
fact, it has a dual membrane structure,
and so, the first portion of the membrane
allows for some things to move in and out.
But then, you have a second
membrane structure that is more
will separate the structures to
a little bit greater degree.
And this will be important
for such things as oxidative
phosphorylation and production
of energy within the cell.
The nuclear envelope is another
kind of partition that we have.
It is not exactly like the other
cell membrane structures.
It has some larger pores in it that allow
for some molecules to move in and out,
and that is helpful for
signaling and trafficking.
The final thing that we have
is a vesicle membrane or --
and these vesicles usually are butted off
from things like the Golgi apparatus
and will eventually dock and
fuse into the cell membrane,
spilling its contents out into
the extracellular environment.
Okay, so now let’s talk
a little bit about why
in the world do you
have partitions anyway?
And I think the best way to think about
why partitioning things within a cell
is think about your own
apartment or your own house.
Why do you have walls within your
particular apartment or house?
And why would that be important
or how is that sometimes helpful?
So, why have these partitions?
Well, I think this basically
occurs often when you want to do a
specific task within a certain
room, for example, cooking.
Sometimes it’s advantageous
to cook within one room
and keep that separate from
the rest of the house.
Maybe you’re making something
that has a certain aroma
or smell to it that you want
to keep within that room.
Or maybe you have certain
tasks that you want to do at
other parts of the house or
apartment such as sleeping,
but yet you have an apartment mate
or you have another person that’s
living with you that that person
is not ready to go to bed yet.
So, by partitioning out that,
it’s easier to have one function
occurring such as sleeping.
So how are these particular
Well, you’re going to have an
inner wall and outer walls,
and as you know, usually, you have thicker
outer walls than you will have inner walls.
But what are these particular
membranes made of?
So we’ll spend a couple of minutes talking
about how they’re specifically made up,
what their sizes are, and how that
structure affects its function.