Urea cycle

Question 1

Enzymes use in step 1 of urea cycle and their function

Answer 1

Carbamoyl Phosphate Synthetase I (CPS I):

FX: catalyzes the formation of carbamoyl phosphate from ammonia and bicarbonate.

first and rate-limiting step of the urea cycle.

Question 2

Enzymes use in the step 2 of urea cycle and their function

Answer 2

Ornithine Transcarbamylase (OTC):

FX: catalyzes the transfer of carbamoyl group from carbamoyl phosphate to ornithine, producing citrulline.

Occur in mitochondria (MCQ)

Question 3

Enzymes use in the step 3 of urea cycle and their function

Answer 3

Argininosuccinate Synthetase:

FX: This enzyme combines citrulline with aspartate to form argininosuccinate.

Question 4

Enzymes use in the step 4 of urea cycle and their function

Answer 4

Argininosuccinate Lyase:

FX: catalyzes the cleavage of argininosuccinate into arginine and fumarate.

Question 5

Enzymes use in the step 5 of urea cycle and their function

Answer 5

Arginase:

FX: Final enzyme in the urea cycle, converting arginine into urea and ornithine.

Question 6

disease related to urea cycle

Answer 6

refer to printed notes