Which statement correctly completes the statement ?
Except for glycine, which is achiral, all the amino acids present in proteins ………………

Options

A. are chiral, but racemic
B. have the L configuration at their `alpha` carbon
C. have the R configuration at their `alpha` carbon
D. have the configuration at their `alpha` carbon

Answer

B

Explanation

Amino acids which combine into peptide to form the building blocks of a rest array of proteins are all L - steroisomers (left handed)
Glycine `NH_2 - CH_2 - COOH`
L - Amino acid `NH_2 - underset( R) underset(|)(CH- COOH`