Question

11-34 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.
Name three mechanisms that a cell can use to restrict a protein to a particular place in the
cell membrane.

Answer 1

Cells use mechanisms such as anchoring to the cytoskeleton, lipid rafts, and protein interactions to restrict proteins to specific areas in the cell membrane.

Step-by-step explanation:

While cell membranes are fluid, allowing proteins to move laterally within the lipid bilayer, cells have mechanisms to localize proteins to specific membrane domains. Here are three such mechanisms:

• Anchoring to the cytoskeleton: Proteins can be restricted in their movement by direct or indirect connections to the cell's cytoskeleton. This anchors them in place and can confine them to certain areas.
• Lipid rafts: These are microdomains within the cell membrane rich in cholesterol and sphingolipids that tend to be more ordered. Certain proteins preferentially associate with these rafts, which can serve to localize them within the membrane.
• Membrane protein interactions: Some proteins are kept in place by binding to other stationary proteins or to specific lipids in the membrane, such as those connected to the extracellular matrix or to proteins on the surface of adjacent cells.