b) With the aid of a labeled diagram, describe the
structure and functions of Golgi apparatus.
Answer:
All eukaryotic cells can find the Golgi apparatus. The
Golgi apparatus located near the nucleus and consists of a stack of flattened,
membranous bound sacs called cisternae. In a mammalian cell can consist of 5 to
6 cisternae while in plant cell can consists about 20 or more cisternae. From
the above diagram (three dimension view) their outer convex surface called
trans face while inner concave surface is called cis face. The cisternae at the
cis face are differing from cisternae at the trans surface in terms of
thickness. The cis face located near the rough endoplasmic reticulum and
nucleus. The transport vesicles are bud off from the endoplasmic reticulum will
fuse at the cis face of the golgi body. The trans face located far away from
the nucleus and endoplasmic reticulum. It is sort the certain substances after
modified such as lipids and proteins and then direct them to their
destinations.
Function: Golgi apparatus receives, modified, processing
and sorts secretory proteins arriving from cis face near the endoplasmic
reticulum to other destinations. For example, the proteins synthesized by
ribosome attached to rough endoplasmic reticulum pass into cisternal space and
then transfer to the Golgi body as a transport vesicle. They are modified and
processing to become a specific enzyme in order carry out certain reactions.
After then, this specific enzyme is packing in secretory enzymes fused into
trans face and bud off to different destinations. This secretory vesicle will
be delivered to other organelles such as plasma membrane, where the content of
vesicle is released to the outside of the cell by exocytosis.
No comments:
Post a Comment