Answer to Question #341446 in Cell Biology for Triple X

Question

Describe the ways that membrane proteins associate with the lipid bilayer.

Answer 1

Proteins can associate with the membrane in one of three ways. Intrinsic or integral membrane proteins embed in the hydrophobic region of the lipid bilayer. Transmembrane proteins are the classic examples of intrinsic membrane proteins. These span the membrane, typically in an α-helix conformation and can span the membrane multiple times. Some intergral membrane proteins use β-barrels to cross the membrane. These structures are typically large and form water filled channels. Extrinsic or peripheral membrane proteins associate loosely with the hydrophilic surfaces of the lipid bilayer or intrinsic membrane proteins. They form weak hydrophobic, electrostatic or non-covalent bonds, but do not embed with the hydrophobic core of the membrane.