The Urea Cycle - Video Tutorials & Practice Problems
The Urea Cycle Concept 1
The Urea Cycle Example 1
Which amino acid provides the NH4+ for the formation of carbamoyl phosphate?
α-ketoglutarate
Glutamine
Glutamate
Aspartate
Which of the following amino acids is not a part of the urea cycle?
Asparagine
Argininosuccinate
Arginine
Ornithine
The Urea Cycle Concept 2
The Urea Cycle Concept 3
The Urea Cycle Concept 4
The Urea Cycle Example 2
The Urea Cycle Concept 5
The Urea Cycle Concept 6
The Urea Cycle Concept 7
The Urea Cycle Example 3
What is the function of aspartate in the urea cycle?
Produces CO2 for carbamoyl phosphate synthesis.
Provides –NH2 group as ammonium ion.
Produces succinate for citrulline formation.
Provides the second nitrogen atom for urea.
Which one of the following sentences is an incorrect description of a reaction in the urea cycle?
Citrulline condenses with aspartate to produce argininosuccinate.
Hydrolysis of arginine produces urea and regenerates citrulline.
Transfer of carbamoyl group from carbamoyl phosphate to ornithine produces citrulline.
Argininosuccinate undergoes cleavage to produce arginine and fumarate.
The Urea Cycle Concept 8
The Urea Cycle Concept 9
The Urea Cycle Example 4
Which of the following metabolites is hydrolyzed in the urea cycle to produce ornithine and urea?
Citrulline
Arginine
Aspartate
Argininosuccinate
Which enzyme catalyzes the reaction of citrulline with aspartate to produce argininosuccinate?
Succinate dehydrogenase
Argininosuccinate lyase
Argininosuccinate synthetase
Arginine oxidase
Write the total number of amino acid metabolites in the urea cycle. How many of those amino acids are not found in proteins?
5, 2
4, 3
4, 2
5, 3