Which membrane protein is attached to the membrane surface?

Which membrane protein is attached to the membrane surface?

• A. Peripheral proteins
• B. Integral proteins
• C. Channel proteins
• D. Transport proteins

Answer: (A)

Proteins associated with membranes fall into two common locations: peripheral proteins that sit on the membrane surface and do not cross the bilayer, and integral proteins that are embedded and often span the membrane. Peripheral proteins attach to the membrane through ionic or hydrogen bonds with lipids or with integral proteins, so they can be removed without disrupting the membrane’s hydrophobic interior. Integral proteins, in contrast, are embedded and typically cross the membrane; channel proteins are a type of integral protein that forms a pore, and transport proteins include those that span the membrane to move substances. Therefore, the membrane protein attached to the surface is peripheral proteins.

Proteins associated with membranes fall into two common locations: peripheral proteins that sit on the membrane surface and do not cross the bilayer, and integral proteins that are embedded and often span the membrane. Peripheral proteins attach to the membrane through ionic or hydrogen bonds with lipids or with integral proteins, so they can be removed without disrupting the membrane’s hydrophobic interior. Integral proteins, in contrast, are embedded and typically cross the membrane; channel proteins are a type of integral protein that forms a pore, and transport proteins include those that span the membrane to move substances. Therefore, the membrane protein attached to the surface is peripheral proteins.