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.

c

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