Where does gluconeogenesis occur?

Correct Answer: C

Rationale: Gluconeogenesis mainly occurs in the liver. It is a process where glucose is synthesized from non-carbohydrate sources such as amino acids and glycerol. The liver is the primary site for gluconeogenesis due to the presence of key enzymes and substrates required for this process. Muscles do not play a significant role in gluconeogenesis, making choice A incorrect. The pancreas is involved in the regulation of blood sugar levels through insulin and glucagon but is not the primary site for gluconeogenesis, so choice B is incorrect. The spleen is not a major organ involved in glucose metabolism, making choice D incorrect.

Correct Answer: A

Rationale: Glucose serves as a primary source of energy for the body, especially for the brain and muscles. Choice B is incorrect because glucose itself is not responsible for transporting oxygen to cells. Choice C is incorrect as glucose is converted to glycogen, not the other way around. Choice D is incorrect as glucose itself does not play a direct role in maintaining body weight.

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: B

Rationale: In a low-carbohydrate diet, fats become the primary source of calories as carbohydrate intake is restricted. Proteins can contribute to caloric intake but are not the primary source in a low-carbohydrate diet. Carbohydrates are intentionally limited in this diet, so they do not supply most of the calories. Vitamins are essential nutrients but do not provide calories.

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.