Okay, so, if we're gonna have a cell. This is any cell.
This is not necessarily a smooth muscle cell or a cardiac cell
or a renal tubular epithelial cell.
This is any cell. In order to have a cell that's alive,
it's got to maintain certain basic housekeeping functions.
Things that has -- every cell has to do.
And this is before we specialize it.
So, it has to be able to interface with the outside world.
You have to have an inside cystocele, cytoplasm,
and an outside world and you need to be able to have
some sort of interface between the two.
Once I've created that barrier, I need to be able to move things across it.
I have to get nutrition in and wastes out.
So, I can't just create a barrier and I'm good to go. It's like a balloon.
No, I gotta be able to move things across the membrane.
Cells have got to be able to communicate.
Even cells that kind of live all by themselves need to communicate
and get various messages, either soluble messages or messages that are mechanical.
And so, there has to be a way to link
and provide signaling from the outside world to the inside world,
say, the nucleus of any cell. Every cell has got to be able to move
and it's gotta have a structure.
Again, I've already said that most cells are not round.
How do I make a cube? How do I make a cell into a cube?
How do I make it into a column? How do I make it into a little pyramid?
Well, in fact, that structure, we're gonna talk about
and how we do that and similarly, how do cells move from one area to another?
No one picks them up. They actually have to kind of slide or walk
or somehow get from one place to another
because they need to get to a new place during development,
need to get to a new place during wound healing,
need to get to a new place because they are responding to particular stimuli.
Every cell constantly turning over, every part of it, constantly turning over,
so, we're constantly synthesizing and we need to talk about the synthetic machinery.
Since everything is balanced, we have degradation.
So, just as we're synthesizing something, we're degrading old stuff
and that's really a nicely balanced pro and anti
just like all the other things we talked about pro and anti, synthesis
and degradation and they have to be balanced
and we'll talk about how we degrade little things
and how we degrade much bigger things.
All of this runs on the currency of ATP. How do we generate energy?
We'll talk briefly about that ATP generation
but mainly we're gonna talk about is what else mitochondria do and that's not just ATP.
And then, finally, the whole gemisch, the whole shoot and match has gotta turnover.
Not only do individual organelles have to turnover,
the whole cell has to turnover and divide and make new ones
and each new cell's gotta have the right complement of mitochondria
and peroxisomes and endosomes and all that other stuff.
So, there's gotta be a very careful regulation of the entire show
and that regulation occurs because of the nucleus and we'll talk a bit about that.
So, these are the basic housekeeping functions
and we will cover these in each of the topic discussions.
For today, we're gonna now mostly focus on plasma membrane
and the plasma membrane is gonna be at the interface with the outside world.
Yup, got that. It's gonna be important for regulating movement across membranes
and it's gonna be important for communication.
So, the plasma membrane is kind of important.
Of course, everything else is important, too.
Motility and structure driven by the cytoskeleton
and we'll talk about that in a separate topic discussion.
Synthesis, rough endoplasmic reticulum, RER, smooth endoplasmic reticulum,
smooth ER, SER, and gogli apparatus.
These are all important for synthesis of new proteins
and new lipids and all the other structures.
And then, degradation, lysosomes, proteasomes, peroxisomes.
Energy comes from mitochondria.
The control of self-replication, that's the nucleus
but some of that also happens at the organeller level as we will talk about.
As promised, we're gonna focus in this topic discussion
on the plasma membrane and specifically, interface with the outside world.