Explain why polar and ionic R groups are hydrophilic.

Explanation:

They are hydrophobic. About 5 amino acids have polar side chains, R-groups which do not ionize or become positively or negatively charged. These R-groups are neither strongly hydrophilic nor hydrophobic. Atoms in long molecules, such as polypeptides, are not rigidly fixed in space or position

Answer;

B. Amount of energy available as fuel for the body.

Explanation;There are three main sources of energy to the body namely; the proteins, carbohydrates, and fats or lipids. Each of these food types is associated with a specific provision of energy in calories per 1 gram. Carbohydrates are the main source and the preferred sources of energy to the body, they breakdown to glucose which acts as an immediate source of energy. Proteins and carbohydrates generates 4 calories of energy per gram while fat provides the most, 9 calories of energy per gram.