In case of alkaptonuria, homogentisic acid is excreted in urine in large amounts. The development of this disease is associated with a disorder of metabolism of the following amino acid:

A. Phenylalanine

B. Methionine

C. Asparagine

D. Alanine

E. *Tyrosine

Symptoms of pellagra (vitamin PP deficiency) is particularly pronounced in patients with low protein diet, because nicotinamide precursor in humans is one of the essential amino acids, namely:

A. Lysine

B. Threonine

C. *Tryptophan

D. Arginine

E. Histidine

A patient has been admitted to the contagious isolation ward with signs of jaundice caused by hepatitis virus. Which of the symptoms given below is strictly specific for hepatocellular jaundice?

A. Bilirubinuria

B. Cholemia

C. Heperbilirubinemia

D. *Increase of ALT, AST level

E. Urobilinuria

Decarboxylation of glutamate induces production of gamme-aminobutyric acid (GABA) neurotransmitter. After breakdown, GABA is converted into a metabolite of the Citric acid cycle, that is:

A. Fumarate

B. *Succinate

C. Oxaloacetate

D. Malate

E. Citric acid

Increased hdl levels decrease the risk of atherosclerosis. What is the mechanism of hdl anti‑atherogenic action?

A. They activate the conversion of cholesterol to bile acids

B. They are involved in the breakdown of cholesterol

C. They promote absorption of cholesterol in the intestine

D. They supply tissues with cholesterol

E. *They remove cholesterol from tissues