4. I. Introduction
The Golgi apparatus is an organelle present in most
eukaryotic cells. It is made up of membrane-bound sacs, and
is also called a Golgi body, Golgi complex, or dictyosome.
Made up of flat membranes called cisternae, the Golgi
apparatus also protects against cell destruction known as
apoptosis.
Golgi was discovered by an Italian physician and noble
laureate Camillo Golgi in 1898 during an investigation of the
nervous system.
5. II. Location
The Golgi apparatus is present in all Eukaryotic cells.
It is absent in few cell types, such as mammalian
RBCs, plants sieve tubes.
In secretory and absorptive cells, it usually lies
between the nucleus.
Plant cells usually have several small Golgi complex,
called Dictyosomes, scattered throughout cytoplasm.
6. III. Structure
The Golgi apparatus is made up of sacs called cisternae. Usually
five to eight cisternae are present in one Golgi apparatus, but as
high a number as sixty cisternae have been observed by
scientists. These bundles of sacs have five distinct and functional
regions, and each region has different enzymes to help it modify
the contents, depending on where they are to end up.
Golgi complex varies in size and form in different cell types.
Cell may have one large Golgi complex or several very small ones.
It occupies different positions in different kind of cells.
7. IV. Functions
The Golgi apparatus is a major collection and
dispatch station of protein products received
from the endoplasmic recticulum (ER).
Proteins synthesized in the ER are packaged into
vesicles, which then fuse with the Golgi
apparatus.
These cargo proteins are modified and destined
for secretion via exocytosis or for use in the cell.
Golgi packages and labels protein items which
are then send to different parts of the cell.
8. IV. Functions
Golgi apparatus is responsible for handling
macromolecules which are required for
proper cell functioning.
The Golgi apparatus works in unison with the
endomembrane system.
The Golgi apparatus is sometimes compared
to a post office inside the cell since one
major function is to modify, sort, and
package proteins to be secreted.
Macromolecules – Molecule necessary for
life
9. IV. Functions
Proteins, as well as lipids and polysaccharides, are
transported from Golgi apparatus to their final
destinations through the secretory pathway.
This involves the sorting of proteins into different
kinds of transport vesicles, which bud from
the trans Golgi network and deliver their contents to
the appropriate cellular locations.
Polysaccharides – Carbohydrate molecules
10. IV. Functions
Some proteins are carried from the Golgi to plasma
membrane by a constitutive secretory pathway, which
accounts for the incorporation of new proteins and lipids
into the plasma membrane, as well as for the continuous
secretion of proteins from the cell.
Other proteins are transported to the cell surface by a
distinct pathway of regulated secretion or are specifically
targeted to other intracellular destinations, such as
lysosomes in animal cells or vacuoles in yeast.
11. Synthesis in plants
Synthesis in Plants – Cell Wall Components
Non cellulose polysaccharides which form part of the cell walls in
plants get synthesized.
After they are synthesized, they get sent to the plasma
membrane, they are added to cellulose.
When added to cellulose, it is assembled on the exterior part of
the cell wall.
Polysaccharides – Carbohydrate molecules
