Threonine is a standard amino acid with a polar side chain. Identify the chiral centers in threonine. a. the carboxyl carbon b. the amino nitrogen c. carbon b d. carbon c e. carbon a

Threonine has two chiral centers.

The correct options are c. carbon b and d. carbon c

Explanation:

Chiral centers are those that have four different groups of atoms bonded to it. Carbon a has three atoms of hydrogen attached to it so it can't be a chiral carbon. It isn't the carboxyl carbon either since it is double bonded to oxygen. And the amino nitrogen does not qualify anyway because it is bonded to three different groups of atoms, not four.