Question: Multisystem Processes & Disorders
A first-year medical student is studying how integral membrane proteins remain anchored within the lipid bilayer. Which of the following best explains the mechanism that holds an integral membrane protein within the membrane?
Choose one answer.
Explanation
Correct answer: C. Hydrophobic interactions between nonpolar amino acid side chains and the fatty acyl tails of the bilayer
Integral membrane proteins span the hydrophobic core of the bilayer, where their membrane-embedded segments are rich in nonpolar amino acids. These nonpolar side chains interact with the fatty acyl tails of the phospholipids through hydrophobic interactions, anchoring the protein in the membrane. Peripheral membrane proteins, by contrast, associate with the polar head groups through electrostatic and hydrogen bonds and are easily displaced.
Learning objective: Explain that hydrophobic interactions anchor integral membrane proteins in the bilayer.
Want this back right before you'd forget it?
Ebb Deck brings back 1,500 USMLE Step 1 questions like this one with spaced repetition, on the web and on iPhone. Your first 100 are free.