Question

There are two extreme models proposed for the movement of molecules across the polarized structure of the Golgi apparatus, the vesicle transport model and the cisternal maturation model.

1. Match a diagram to a model and discuss each model.
a. What are the roles of vesicles in forward movement of proteins across the stacks?

(this will be different for each model and you do not need to discuss budding from

the ER to the Golgi)
b. How would Golgi resident proteins be maintained in individual stacks ?

2.Which model do you favor and why? (purely conjecture)

Answer 1

in the cisternal maturation model vesicles formed from endoplasmic reticulam will form via sisternae and it will mature to trans cisternae through a medial cisternae. once it reach trans cisternae proteins will be separated as cargo to each part of the cell and reaches the cell surface as vesicle.

in vesicle transport model no maturation of cis medial trans cisternae. everything remains in its place. COPI delivers vesicles to each cisternae and in trans cisternae the destined proteins will be separed to its deatined place.

B) Golgi reaisdent proteins in each stack:

Golgi residant enzymes present in each cisternae. Each cisternae has enzymes for different post translational modifications such as glycosylation and acetylation

2. I support vesicle support model since the model in this theory supports vesicle movement through each cisternae and the cisternae remains in its place without movement. This looks like an already formed Golgi apparatus for protein sorting and modifications