The urea cycle is vital to the excretion of ammonia, a harmful byproduct of amino acid breakdown.

What enzyme in the urea cycle converts L-ornithine to L-citrulline?

The enzyme responsible for the reaction that produces ammonia during amino acid deamination is ___________.

Which of the following is a possible consequence of an arginase deficiency?

What enzyme is deficient in Lesch-Nyhan syndrome?

Which of these describe(s) the role of aminotransferases in protein catabolism?

I. They are present in the liver and muscle

II. They transfer the amino group from one amino acids to alpha-ketoglutarate

III. In the muscle, these enzymes move the amino group to glutamate, which can be further converted to glutamine which is a excess nitrogen carrier from tissues

IV. They catalyze irreversible reactions and release amino groups as free ammonium

Which of the following classes of enzymes could possibly breakdown collagen, the most common protein in the human body?

Which of the following regarding mitochondrial carbamoyl phosphate synthetase are true?

I. Mitochondrial carbamoyl phosphate synthetase forms intermediates in the urea cycle

II. Mitochondrial carbamoyl phosphate synthetase utilizes adenosine triphosphate (ATP)

III. A decrease in normal levels of the enzyme leads to a decrease in ammonium ions in the blood

IV. Mitochondrial carbamoyl phosphate synthetase converts ammonium ions to carbamoyl phosphate

Which of these describe the role of ornithine transcarbamoylase in protein degradation?

I. Ornithine transcarbamoylase converts carbamoyl phosphate to citrulline in the presence of ornithine

II. Ornithine transcarbamoylase is present in the mitochondria

III. Deficiency of the enzyme leads to a decrease of ammonium ions in the blood

IV. Deficiency of the enzyme leads to an increase in urea in the blood

Which of the following describes the role of glutamine synthetase in protein catabolism?

I. Glutamine synthetase converts glutamate and ammonia to glutamine using one molecule of ATP

II. The reaction catalyzed by glutamine synthetase is reversible

III. The reaction catalyzed by glutamine synthetase removes excess nitrogen (in the form of toxic ammonia) from protein degradation

IV. Glutamine synthetase converts glutamine to glutamate