Biomolecules Question 21
21. The secondary structure of that portion of an integral protein that is buried in the lipid bilayer of a cell membrane is
[1999]
(a) b-strand
(b) b-bend
(c) random coil
(d) a-helix
Show Answer
Answer : d
Hints & Solutions
(d) Secondary structure is development of new stearic relationships amongst the amino acids through formation of intra and inter polypeptide hydrogen bonds. Secondary structure refers to regular, recurring arrangements in space of adjacent amino acid residues in a polypeptide chain. It is maintained by hydrogen bonds between amide hydrogens and carbonyl oxygens of the peptide backbone. The major secondary structures are $\alpha$-helices and $\alpha$-structures.
