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Golgi Apparatus
By Kirsten Lydon
What is a Golgi apparatus?

Sometimes called a Golgi body

A flattened stack of membranes that form a
complex structure

Individual stacks are called cisternae
 Latin

for “collecting vessels”
Cisternae vary in number
1
to a few in protists
 20
or more in animal cells
 Several
hundred in plant cells
Artist’s depiction
Real life image
What does it do?

Functions include the collection, packaging, distribution,
and modification of molecules

These molecules are synthesized in one location of the
cell and are used in another.

Some may leave the cell through the cellular membrane

Like the mailroom of the cell
A vesicle
transporting
proteins out of the
cell
What does it do? (cont.)


Proteins and lipids made on the rough and smooth endoplasmic
reticulum (ER) are modified as they pass through the Golgi apparatus
ex. The addition or modification of short sugar chains which make:


Glycoproteins and glycolipids
It also synthesizes cell wall components

Noncellulose polysaccharides that form the cell wall of plants are
synthesized in the Golgi body.

Afterwards, they are sent to the plasma membrane and are added
to cellulose which assembles the exterior of the cell.
The Golgi doing different jobs
It has a front and back

The front is called the cis face
 Usually found near the ER
 Materials enter the Golgi body in transport vesicles that
come from the ER
 Lumen
 Cavity
where proteins, to be secreted by the cell, are
packaged in vesicles to be released

The back is called the trans face
 Materials are discharged from this face in secretory vesicles
 Lysosomes
 Come
from the Golgi apparatus
 Contain a high level of degrading enzymes
How does it move materials?


It is proposed that material moves through the cell by means
of:

cisternal maturation

Transport of vesicles between cisternae

And direct tubular connections
The primary accepted method of transport is cisternal
maturation


When individual cisternae mature from early cis to late trans
Because the cisternae are so tightly stacked together it is hard
to give a definitive answer as to how transport actually occurs.
Protein transport through endomembrane system
Connected to Alzheimer's disease

It is an irreversible, progressive brain disease that slowly
destroys memory and thinking skills.

Causes dementia and eventually death

In Alzheimer’s disease, the Golgi bodies seem to fall
apart or become fragmented as it progresses.