Proteins LM6: Transamination and Deamination Reactions

Most ammonia generated in the body normally comes from the oxidative deamination of which amino acid?

• Ala

• Glu

• Asn

• Asp

• Gln

Which one of the following coenzymes carries one-carbon fragments from amino acids to intermediates of purine and pyrimidine nucleotides?

• Glutamine

• a-Ketoglutarate

• Tetrahydrofolate

• Aspartate

• Vitamin B12

Which one of the following enzymes is involved with the conversion of aspartate and a-ketoglutarate to oxaloacetate and glutamate, respectively?

• ALT

• GLDH

• SGPT

• SGOT

• Asparagine synthetase

Glutamate dehydrogenase is present in all of the following, EXCEPT:

• Erythrocytes

• Liver

• Kidney

• Brain

• Muscle

There are no known metabolic defects associated with the conversion of a-KG= to Glu, Ala to pyruvate, Asp to OAA, or Gln to Glu. This indicates that:

• a. These reactions are unimportant.

• b. These reactions are essential for life

• .

  c. Investigators have been largely funded to do

  other studies.

• d. Investigators have withheld information from

  us.

• e. Amino acid catabolism is unessential for life.

Essentially all of the a-amino nitrogen from amino acid catabolism can be funneled through:

• Acetyl-CoA

• a-Keto acids

• Catalase

• Asparagine

• Glutamate

The oxidative deamination of glutamate yields NH4+ and:

• NAD+

• Oxaloacetate

• Gln

• Pyruvate

• a-KG=

The primary end-product of nitrogen metabolism in mammals is:

• NH3

• NH4+

• Urea

• NADH

• Uric acid