Question

Integral membrane proteins generally:

A) are bound to the membrane indirectly through interactions with other membrane proteins
B) are anchored in the membrane by covalent binding to lipid molecules in the membrane
C) do not enter the phospholipid bilayer
D) have one or more transmembrane domains that interacts with the hydrocarbon core of the phospholipid bilayer.

Answer 1

Option (D), Integral membrane proteins are embedded in the plasma membrane with transmembrane domains interacting with the lipid bilayer's hydrocarbon core.

Step-by-step explanation:

Integral membrane proteins generally have one or more transmembrane domains that interact with the hydrocarbon core of the phospholipid bilayer. These proteins are permanently embedded within the plasma membrane and serve critical roles such as facilitating the transport of molecules across the membrane and acting as cell receptors.

A typical integral membrane protein spans the entire membrane with hydrophobic domains that interact strongly with the fatty acid interior of the membrane, while hydrophilic domains face the cytosol or external environment.

Unlike integral proteins, peripheral proteins are more loosely associated with the membrane surface, often attached indirectly through interactions with other membrane proteins, phospholipid head groups, or by hydrogen bonding and electrostatic forces.