Question

Which of the following best describes the source of the carbon skeleton for synthesizing non-essential amino acids?

A.    Glutamate

B.     Acetyl coenzyme A

C.     Carbohydrates

D.    Essential amino acids

The use of proteins for energy begins with which of the following processes?

A.    Deamination

B.     Hydroxylation

C.     Oxidation

D. Polymerization

A 56-year-old woman with chronic liver disease is brought to the physician because of confusion, a depressed level of consciousness, personality changes, and intellectual impairment. Laboratory tests support a diagnosis that the woman is suffering from liver encephalopathy. Which of the following blood factors is the most likely cause of this condition?

A.    Ammonia

B.     Ammonium

C.     Arginine

D.    Citrulline

Which of the following substances best describes deaminated alanine?

A.    Acetoacetic acid

B.     Acetyl coenzyme A

C.     Glucose

D.    Lactic acid

E. Pyruvic acid

An increase in blood levels of which of the following substances promotes breakdown of proteins in most tissues?

A.    Estrogen

B.     Glucocorticoid

C.     Growth hormone

D.    Insulin

Answer 1

Answer 1) option A. Glutamate

Explanation - Nonessential amino acids can be synthesized in the body, whereas essential amino acids must be obtained in the diet.Nonessential amino acids are synthesized by most of the cells, including hematopoietic lineages. Nonessential amino acids are mainly synthesized from glucose alanine, arginine from the urea cycle in hepatic cells asparagine, aspartate, cysteine, glutamate, glutamine, glycine, proline, and serine), except for tyrosine, which is synthesized from phenylalanine.

Answer 2) option A) Deamination.

Explanation - Deamination is the removal of an amino group from a molecule. Enzymes that catalyse this reaction are called deaminases. In the human body, deamination takes place primarily in the liver,it can also occur in the kidney. In situations of excess protein intake, deamination is used to break down amino acids for energy. The amino group is removed from the amino acid and converted to ammonia.

Answer 3) option A) Ammonia.

Explanation-Ammonia is the best characterized neurotoxin that precipitates liver encephalopathy. For clinical practice measuring ammonia concentration may be useful under certain conditions. The longstanding warning that arterial ammonia levels are required has been supplanted by studies showing venous ammonia levels perform almost as well.

Answer 4) pyruvic acid.

Explanation - Alanine can be synthesized from pyruvate and branched chain amino acids such as valine, leucine, and isoleucine.Alanine is produced by reductive amination of pyruvate, a two-step process.

Answer 5) option C) Growth hormone.

Explanation-Growth hormone stimulates protein anabolism in many tissues. This effect reflects increased amino acid uptake, increased protein synthesis and decreased oxidation of proteins.