GOLGI COMPLEX
Golgi complex
represents a differentiated part
of endo membrane
system . It
occurs between ER and
plasma membrane. The part
of cytoplasm where golgi body occurs is
free from ribosomes,
glycogen and mitochondria. This part is
called zone of
exclusion.
Ultra structure of Golgi body:-
Golgi complex has
dictyosomes . Dictyosomes
consist of stack of curved
disc like structures called cisternae. Cisternae have dilated
peripheral rigion. They are
associated with vesicles and
tubules.
Dictyosome
shows prolarization which
is called cis-trans
axis. Its convex side is called
proximal or forming or cis face while concave
side typing toward plasma membrane
is called distal, maturing
or trans face.
Proximal face has
fenestrated appearance due to
fusion of transitional vesicles.
CHEMICAL
COMPOSITION OF GOLGI BODY:-
Chemical composition
of membrane of
Golgi complex is
intermediate between that
of plasma membrane
and ER.
Its membrane has
glycosyl transferase and
thiamine pyrophosphatase .
ROLES OF GOLGI BODY:-
1.
The
most important function
of golgi complex
is secretion .Various substances
being synthesized by
ER are released
through transitional vesicles.
Transitional vesicles develop
as bleb from
ER . They fuse at cis face
of golgi body . Within Golgi body
concentration and packaging
of substances occur.Golgi body
releases substances through
secretory vesicles. Secretory vesicles
fuse to plasma
membrane to release
substance.
2.
Golgi
body is involved
is recycling of plasma
membrane.
3.
It
is responsible for
cell plate formation during cytokinesis
in plant cell division.
4.
It is
responsible for acrosome
formation . Acrosome occurs
in sperm
head . It has sperm
lysine.
5.
It is
involved in lysosome formation.
6.
It is
involved in sulphation
of protein.
7.
It
is involved in
glycosidation of lipid and
protein.
GERL:- Often a
saccular structure that is
rich in acid
phosphatase is associated with
trans face of
dictyosome. It is called GERL.
Acid phosphatase is
the characteristic enzyme
of lysosome. GERL is
implicated in formation
of primary lysosomes . It is
involved in formation of
melanin granules, in
the processing and
packaging of secretory
material in endocrine and exocrine
cells and in
lipid metabolism.
It is
interpreted as a site
involved in sorting
out of proteins.