The LDL receptor is an integral membrane protein that extends both outside and into the interior of the cell.The amino acid side chains (R groups) in the region of the protein that crosses the membrane are most likely
A) polar.
B) hydrophilic.
C) hydrophobic.
D) carbohydrates.
E) lipids.

Question

Quizplus · Accepted Answer

The region of the LDL receptor that crosses the membrane is a transmembrane domain, and these domains are typically composed of hydrophobic amino acid side chains (R groups) that interact with the hydrophobic interior of the lipid bilayer. Therefore, the amino acid side chains in this region are most likely hydrophobic.

The LDL Receptor Is an Integral Membrane Protein That Extends