試題詳解

77. Which of the following statements about urea cycle are correct? ① Urea is the end product of the urea cycle. ② Inherited defects in urea cycle cause hyperammonemia. ③ The synthesis of fumarate by the urea cycle can be used as a precursor for glucose synthesis. ④ The urea cycle begins with the formation of ornithine in mitochondria. ⑤ ATP is not consumed in urea cycle.
(A) ②③④
(B) ②③⑤
(C) ①②③
(D) ①④⑤
(E) ③④⑤