00:01
The next important structure
in our cells is the ribosomes.
00:06
And the ribosomes are important because
this is where we synthesize all of our proteins.
00:12
So the process of translation
occurs at the ribosomes.
00:18
The ribosomes is actually made
up of two subunits of ribosomal RNA
with some proteins also mixed in together.
00:26
And together those two
units thread through mRNA
on one side and out on the
other side, you get proteins.
00:35
So switching gears, the endoplasmic reticulum is first
of several organelles that we will discuss today.
00:43
The endoplasmic reticulum is going
to be located just off of the nucleus
and extend into the cytoplasm of the cell.
00:52
There are two different types
of endoplasmic reticulum.
00:55
The rough endoplasmic reticulum
also known as the rough ER
and the smooth endoplasmic
reticulum also known as the smooth ER.
01:04
These two both have very different functions where the
rough endoplasmic reticulum is gonna be responsible
for modifying proteins that are
being translated on their surface.
01:18
whereas the smooth ER is responsible for the production
of different lipids as well as steroid hormones.
01:25
The smooth ER is also
important for detoxification
which is why liver cells have
an extensive network of Smooth ER.
01:39
Extending from the ER, the next major organelle is
going to be the golgi complex or the golgi apparatus.
01:48
the golgi apparatus is actually directional where
the part of the Golgi that is closest to the nucleus
is referred to as the cis-golgi and the part that is further
away from the nucleus is referred to as the trans-golgi.
02:05
Transport vesicles containing proteins leaving the
ER are transported to the cis side of the golgi
where they are further processed in the cell.
02:17
I like to think of the golgi as
kind of like a 'FedEx' in our cell
and the reason why is beacuse a lot of
sorting and packaging occurs in this organelle.
02:27
Specifically things come in, they are
modified or tagged with a certain zip code
and then told where to go next.
02:37
If something is destined
to be secreted from the cell,
it will always go through the golgi first and then
from there, be taken to the plasma membrane.
02:48
And they can also be taken to other
parts of the cell and other organelles as well.
02:55
So all these together, give us
our endomembrane system.
03:00
The endomembrance system starts with
the nucleus which we will discuss shortly,
and after that goes to the ER followed by
the golgi and then to the plasma membrane.
03:12
And so something that is synthesized at the
ER can eventually be secreted out of the cell
through this transport system involving
these membrane-bound organelles
and the transport vesicles between them.
03:30
So other organelles that are part of the
endomembrane system but are not necessarily
in that pathway toward the outside
of the cell, are things like lysosomes.
03:41
So lysosomes are derived from the golgi
apparatus but these contain digestive enzymes
and it's is actually very
similar to our stomach.
03:51
And what this does is it breaks
down large particles and molecules
into smaller things that
can then be used by the cell.
03:59
So in a way, the lysosome is
like the stomach of our cells.