Question

Cell membranes are fluid, and thus proteins can diffuse laterally within the lipid bilayer. However, sometimes the cell needs to localize proteins to a particular membrane domain. Which choice is NOT a mechanism by cells to restrict membrane protein diffusion?

A. Anchor the proteins to the extracellular matrix
B. Anchor the proteins in the cytoskeleton
C. Utilize tight junctions to restrict proteins to one membrane domain
D. All of the above can be used

Answer 1

All the mechanisms provided, such as anchoring to the extracellular matrix, cytoskeleton, or utilizing tight junctions, are actually used by cells to restrict membrane protein diffusion.

Step-by-step explanation:

The question is asking about the mechanisms by which cells restrict the diffusion of membrane proteins to localized domains within the cell membrane. All of the choices provided anchoring the proteins to the extracellular matrix, anchoring the proteins in the cytoskeleton, and utilizing tight junctions to restrict proteins to one membrane domain—are indeed mechanisms used by cells to accomplish this.

Therefore, the option 'D. All of the above can be used' would be the correct answer to the question about what is NOT a mechanism used to restrict membrane protein diffusion since each mechanism listed actually serves that purpose.