Protein Metabolism

What is transamination?

• Swapping the carboxyl group on a molecule for an amino group.

• Liberating the amino group from an amino acid as free ammonia.

• Swapping the amino group on an amino acid for a carboxyl group.

• Liberating ammonia to molecules to create amino acids.

Serotonin is a chemical in the brain that can affect mood. Which of these amino acids is used for the production of serotonin?

• G

• H

• W

• T

It is the removal of free ammonia from an amino acid

Which of these situations would create a positive nitrogen balance in the body?

• Malnutrition

• Infection

• Pregnancy

• Starvation

The unwanted amino acids abstracted from the tissues are either used up by the tissue or in the liver converted into

• uric acid

• ammonia

• urea

• ammonium salts

Along with CO₂, NH₃ and ATP, the amino acid that is needed in urea cycle is

• Ala

• Asp

• Asn

• Arg

The enzymes of urea synthesis are found in

• Nucleus

• Mitochondria

• Cytosol

• Both mitochondria and cytosol

The 2 nitrogen atoms in urea are contributed by

• Ammonia and glutamate

• Glutamine and glutamate

• Ammonia and alanine

• Ammonia and aspartate

Argininosuccinate cleaved into

• arginine & aspartate

• aspartate & fumarate

• arginine & glycine

• arginine & fumarate

Transfer of the carbamoyl group of carbamoyl phosphate to ornithine is catalyzed by a liver mitochondrial enzyme called

• argininosuccinate

• Ornithine transcarbamoylase

• Carbamoyl phosphate synthetase

• arginase