Ketones are produced when:

Correct Answer: A

Rationale: Ketones are produced when the body uses fat for energy due to the depletion of carbohydrate stores. When carbohydrate stores are depleted, the body turns to fat as its primary source of energy, leading to the production of ketones. Excess protein consumption does not directly lead to ketone production. Similarly, the depletion of protein stores or fat stores is not directly related to the production of ketones.

Correct Answer: C

Rationale: The correct answer is C: Protein synthesis. This process involves the formation of proteins from amino acids to support various body functions. Gluconeogenesis (choice A) is the synthesis of glucose from non-carbohydrate sources, not protein synthesis. Deamination (choice B) is the removal of an amino group from an amino acid, not the synthesis of proteins. Transamination (choice D) is the transfer of an amino group from one molecule to another, not the direct synthesis of proteins.

Correct Answer: B

Rationale: The correct answer is B: nonessential amino acids. Nonessential amino acids can be synthesized by the body, so they do not need to be obtained through the diet. Essential amino acids, choice A, must be obtained from the diet because the body cannot produce them. Choices C and D, complete and incomplete amino acids respectively, do not accurately describe the classification of amino acids based on synthesis by the body.

Correct Answer: A

Rationale: The correct answer is the amino group. Amino groups are functional groups found in amino acids, which are the building blocks of proteins. These groups contain nitrogen and are essential for the structure and function of proteins. The carboxyl group (choice B) contains carbon, oxygen, and hydrogen, while the peptide bond (choice C) is a covalent bond formed between amino acids in a protein chain. The side chain (choice D) refers to the unique chemical structure attached to the central carbon of an amino acid and varies among different amino acids, but it does not specifically contain nitrogen.

Correct Answer: A

Rationale: The correct answer is A: kwashiorkor. Kwashiorkor is a form of protein-energy malnutrition that arises due to a protein-deficient diet. This condition leads to symptoms such as edema, skin lesions, and fatty liver. Choice B, marasmus, is a form of PEM caused by overall malnutrition (protein and calorie deficiency), resulting in severe wasting and muscle loss. Choice C, anemia, is a condition characterized by a deficiency of red blood cells or hemoglobin, not specifically related to protein deficiency. Choice D, beriberi, is a disease caused by thiamine (Vitamin B1) deficiency, not a form of PEM related to protein deficiency.