Question

How can one tell between single and multiple transmembrane proteins? From transmembrane proteins and regular proteins?

A) Number of Beta-Sheets; Presence of Signal Peptide
B) Number of Alpha-Helices; Presence of N-terminal Anchor
C) Number of Disulfide Bonds; Presence of Coiled-Coils
D) Number of Ubiquitin Moieties; Presence of Phosphorylation Sites

Answer 1

Single-pass transmembrane proteins usually have one alpha-helix, while multi-pass proteins have multiple alpha-helices. Integral membrane proteins have an N-terminal anchor, whereas regular proteins do not. The correct option is b.

Step-by-step explanation:

One can differentiate between single and multiple transmembrane proteins based on the number of alpha-helices that span the membrane.

Single-pass transmembrane proteins typically have one alpha-helix, while multi-pass proteins have multiple alpha-helices.

In terms of distinguishing transmembrane proteins from regular proteins, one can look for the presence of an N-terminal anchor. Integral membrane proteins have an N-terminal signal sequence that guides them to the rough endoplasmic reticulum (RER) during synthesis, whereas regular proteins do not have this signal sequence. The correct option is b.