Question

Considering the 'fluid mosaic model' of the cell membrane, which one of the following statements is correct regarding flip-flop movement?

• A. \( \text{Neither lipids nor proteins can flip-flop} \)
• B. \( \text{Both lipids and proteins can flip-flop} \)
• C. \( \text{While lipids can rarely flip-flop, proteins cannot} \)
• D. \( \text{While proteins can flip-flop, lipids cannot} \)

Hint:

Flip-flop movement in membranes requires specific enzymes like flippases and scramblases.

Answer 1

The Correct Option is C

The fluid mosaic model describes the dynamic nature of cell membranes. Lipids can undergo lateral diffusion readily, but flip-flop movement (between monolayers) is rare due to hydrophobic barriers. Proteins, due to their large size and hydrophilic regions, cannot flip-flop spontaneously.