Question

The amino acid side chain residues in an α helix point outwards away from the center of the helix. the amino acid side chain residues in an α helix point outwards away from the center of the helix.

a. True
b. False

Answer 1

Answer: The statement is true.

The α helix structure is stabilized by hydrogen bonds between the oxygen atom of the C=O and hydrogen atom of the N-H group of the amino acid four residues away. In the tightly coiled super helical structure the side chains or the -R groups point outward or away from the helical axis. The main reason for such structure is to avoid steric hinderance due to heavy or bulky -R groups and to keep the α helix structure stable. The right handed α helix is more stable than the left handed α helix as there is lesser steric hinderance between the side chain and the backbone.