Which of the following natural alpha-amino acids is optically inactive?

AValine
BSerine
CAlanine
DGlycine

Answer: D

Glycine is

H X_{2} N - CH X_{2} - COOH

; its alpha-carbon carries two hydrogen atoms, so it is not a stereocentre and the molecule is achiral. Alanine, serine and valine each have four different groups on the alpha-carbon.

Practice Biomolecules More on Amino acids: zwitterions, isoelectric point

Previous questionNext question

More questions on Amino acids: zwitterions, isoelectric point

Which of the following is an essential amino acid (as per the NCERT list)? NEET level
The zwitterionic (dipolar ion) form of glycine is represented by NEET level
Which of the following amino acids is basic in nature? NEET level
Alpha-amino acids react with ninhydrin on warming to give a coloured product. The colour is NEET level
Naturally occurring alpha-amino acids obtained from proteins belong to which stereochemical series? NEET level
Amino acids are crystalline solids with melting points much higher than those of haloalkanes or carboxylic acids of similar molar mass, main... JEE Main level