BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Answer and Explanation: All amino acids have a general structure comprising of an alpha carbon atom, a carboxyl group, an amino group and a hydrogen atom. Therefore, from the options above, only A) Carboxyl functional group is present in all amino acids.

Detailed explanation-2: -Each amino acid has the same fundamental structure, which consists of a central carbon atom, also known as the alpha () carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom.

Detailed explanation-3: -Carboxyl groups are a combination of two functional groups attached to a single carbon atom, namely, hydroxyl (single-bonded OH) and carbonyl (double bonded O) groups. The carboxyl (COOH) group is so-named because of the carbonyl group (C=O) and a hydroxyl group. They include carboxylic acids and amino acids.

Detailed explanation-4: -A functional group may participate in a variety of chemical reactions. Some of the important functional groups in biological molecules are shown above; they include: hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl (R-S-H).