Question

What are the three functional groups that make up the backbone of all amino acids?

• A. Carboxy $\left(COOH\right)$, amino $\left(N{H}_2\right)$, hydrogen $\left(H\right)$
• B. Carbonyl $(C=O)$, amino $\left(N{H}_2\right)$, hydrogen $\left(H\right)$
• C. Methyl $\left(C{H}_3\right)$, carboxyl $\left(COOH\right)$, amino $\left(N{H}_2\right)$
• D. Amino $\left(N{H}_2\right)$, hydroxyl $\left(OH\right)$, carboxyl $\left(COOH\right)$
• E. Amino $\left(N{H}_2\right)$, carbonyl $(C=O)$, methyl $\left(C{H}_3\right)$

Answer 1

Answer: (A)

Carboxy $\left(COOH\right)$, amino $\left(N{H}_2\right)$, hydrogen $\left(H\right)$

Amino acids are small molecules made up of carbon, hydrogen, nitrogen, oxygen and in some cases, sulphur also. Each amino acid has a hydrogen atom (H), free carboxyl group (COOH), free amino group (NH₂) and 'R' as the side chain (variable), attached to a central carbon atom.

So, the correct answer is 'Carboxy (COOH)(COOH), amino (NH₂)(NH2), hydrogen (H)'.