Question

Some amino acids such as Ile, Met, and Leu have nonpolar, aliphatic radical groups, while others such as Ser, Cys, Glu, Pro, Asn, and Thr have polar uncharged radical groups. Where in proteins would you expect to find amino acids such as Ile, Met, and Leu but not amino acids such as Ser, Cys, Glu, Pro, Asn and Thr?

A.on an outside surface interacting with water

B.folded inside a central, core region that does not interact with water

C.not within transmembrane regions that interact with the lipid bilayer

D.in regions where hydrogen bonding is important

Answer 1

B. folded inside a central, core region that does not interact with water

Since Isoleucine, Methionine and Leucine are non-polar side chains, they are typically found in environments without water, such as the core regions of proteins.