Which of the following designations are correct for the naturally occuring amino acid, proline?

Options

A. `R,L`
B. `S,L`
C. `S,D`
D. `R,D`

Answer

B

Explanation

The naturally occuring amino acids, the building blocks of proteins, are all `L-`amino acids. In proline the chiral `C` is aprt of a five-membered ring.

It is attached to an `N` (the amino group) and this part of the ring has first priority. the carboxy`1` group is second and the `C` in the ring bonded to the chiral carbon is third.

This compound is `S`.