Question

1. Cytosolic G-proteins that bind to the neck of a clathrin-coated vesicle to help pinch it off from the donor membrane are called:

A. SNARES

B. Cargo

C. Dynamin

D. Adaptin

E. RABs

2. Sodium ions are unable to pass through a potassium ion channel as a result of which of the following?

A. Their charge

B. The larger size of the Na+ atomic Radii relative to K+

C. Their inability to shed their sphere of hydration to pass through

D. Sodium can only move down it's electrochemical gradient

E. None of the Above

Answer 1

Ans 1. Cytosolic G-proteins that bind to the neck of a clathrin-coated vesicle to help pinch it off from the donor membrane are called:

A DYNAMIN

B SNAREs

C RABs

• Dynamin is a GTPase, which regulates the rate with which vesicles pinch off from the membrane.
• SNAREs proteins seem to have a central role both in providing specificity and in catalyzing the fusion of vesicles with the target membrane. RABs seem to work together with other proteins to regulate the initial docking and tethering of the vesicle to the target membrane.

2. Sodium ions are unable to pass through a potassium ion channel as a result of --

C. Their inability to shed their sphere of hydration to pass through