Multiple Choice
In which cellular compartment are lipids synthesized?
430
views
8. Membrane Structure
The Lipid Bilayer
Multiple Choice
In a phospholipid bilayer, what is the primary role of cholesterol?
A
It forms aqueous channels that allow polar molecules to freely diffuse across the membrane.
B
It modulates membrane fluidity and permeability by buffering the effects of temperature on phospholipid packing.
C
It serves as the main energy-storage molecule within the membrane by being readily hydrolyzed for ATP production.
D
It covalently cross-links phospholipid tails to rigidly lock the bilayer in place.
Verified step by step guidance1
Understand the structure of the phospholipid bilayer: it consists mainly of phospholipids with hydrophilic heads and hydrophobic tails, creating a semi-permeable membrane.
Recognize that cholesterol is a lipid molecule interspersed within the phospholipid bilayer, influencing its physical properties.
Recall that cholesterol does not form channels or serve as an energy source; instead, it interacts with phospholipid tails to affect membrane behavior.
Focus on how cholesterol modulates membrane fluidity: at high temperatures, it stabilizes the membrane by restraining phospholipid movement, and at low temperatures, it prevents tight packing, maintaining fluidity.
Conclude that cholesterol's primary role is to buffer the effects of temperature changes on membrane fluidity and permeability, ensuring membrane stability and proper function.
Related Videos
Related Practice
