Question

What effect does cholesterol have on membrane fluidity?

a. Cholesterol disrupts close packing of fatty acid chains.
b. Cholesterol enhances sharp transition temperature and creates a condition of intermediate fluidity.
c. Cholesterol interferes with the mobility of fatty acid chains.
d. Cholesterol abolishes sharp transition temperature and creates a condition of intermediate fluidity.

(1) a and d
(2) c and d
(3) a and b
(4) b and c
(5) a, c and d

Answer 1

Cholesterol acts as a buffer in regulating membrane fluidity by preventing extreme changes in fluidity caused by temperature. It reduces the lateral mobility of membrane components by filling in gaps between phospholipids.

Step-by-step explanation:

Cholesterol plays a role in regulating the fluidity of the cell membrane. It acts as a buffer, preventing lower temperatures from inhibiting fluidity and higher temperatures from increasing fluidity too much. By filling in gaps between phospholipids, cholesterol reduces the lateral mobility of membrane components, thus decreasing fluidity. Overall, cholesterol extends the temperature range in which the membrane is appropriately fluid and functional.