What three structural groups shown do all amino acids have in common?

All amino acids contain amine (-NH2), carboxyl (-COOH) and R group (side chain) with hydrogen (H).

All of the 20 amino acids coded by genetic code have N-terminus (amine) and C-terminus (carboxyl) and those are called functional groups. The key components of amino acids are hydrogen, oxygen, carbon and nitrogen. They can be classified in different subgroups according to their polarity, the core structural functional groups, side chain group type, pH.

Answer;

-Carboxyl group (COO-)

-Amino group (NH2)

-Central carbon

Explanation;

-Each amino acid consists of a central carbon atom (the α carbon) bonded to a hydrogen atom, a carboxyl group, an amino group, and a specific side chain (designated R).

-Amino acids have a two-carbon bond. One of the carbons is part of a group called the carboxyl group (COO-). A carboxyl group is made up of one carbon (C) and two oxygen (O) atoms. That carboxyl group has a negative charge, since it is a carboxylic acid (-COOH) that has lost its hydrogen (H) atom.