試題詳解

17. Which of the following is not true during fasting?
(A) During fasting, the liver maintains blood glucose levels.
(B) Amino acids from muscle protein are a major carbon source for the production of glucose by the pathway of gluconeogenesis.
(C) As amino acid carbons are converted to glucose, the nitrogens are converted to urea. Thus, the urinary excretion of urea is high during fasting.
(D) As fasting progresses, however, the brain begins to use ketone bodies, sparing blood glucose.
(E) Only muscle proteins are mobilized for energy requirement.