Excretory Products And Their Elimination Ques 42
42. In Ornithine cycle, which of the following wastes are removed from the blood?
[2005] (a) $CO_2$ and urea
(b) Ammonia and urea
(c) $CO_2$ and ammonia
(d) Urea and urine
Show Answer
Answer : c
Hints & Solutions
(c) Urea $NH_2-CO-NH_2$ is formed from two molecules of ammonia and one molecule of carbon dioxide. A molecule of ammonia combines with carbon dioxide to form carbamoyl phosphate. It reacts with ornithine to form citrulline. Citrulline accepts another molecule of $NH_4{ }^{+}$ giving rise to arginine. Arginine is hydrolysed into urea and ornithine with the help of enzyme arginase.
BETA
