Branched-chain amino acid metabolism — Flashcards

Flashcard 1: What is the mode of inheritance of maple syrup urine disease?_____

Answer: Autosomal recessive

Flashcard 2: Maple syrup urine disease is characterized by blocked degradation of _____ amino acids

Answer: branched

Flashcard 3: Are the essential amino acids methionine, valine, and histidine ketogenic or glucogenic? _____

Answer: Glucogenic

Flashcard 4: Thiamine pyrophosphate (B1) is a cofactor for the enzyme _____ (glycolysis)

Answer: pyruvate dehydrogenase

Flashcard 5: Treatment of maple syrup urine disease includes high-dose _____ supplementation

Answer: thiamine

Flashcard 6: What stainable protein is abundant in astrocytes?

Answer: GFAP

Flashcard 7: What enzyme converts pyruvate to alanine?

Answer: alanine aminotransferase (ALT)

Flashcard 8: Role of myeloperoxidase in neutrophils:

Answer: Plays a role in respiratory burst (catalyzes formation of HOCl from H2O2)

Extra: Myeloperoxidase (MPO) is found in the azurophilic granules of neutrophils (PMNs). During the respiratory burst, it converts Hydrogen Peroxide (H2O2) and Chloride ions into Hypochlorous acid (HOCl - bleach), which is a potent bactericidal agent.

Flashcard 9: What reaction is catalyzed by superoxide dismutase during the respiratory burst?

Answer: Conversion of Superoxide ($O_2^-$) to Hydrogen peroxide ($H_2O_2$)

Extra: Superoxide dismutase (SOD) neutralizes superoxide radicals. Reaction: 2O2- + 2H+ -> H2O2 + O2. Clinical Pearl: Mutations in superoxide dismutase 1 (SOD1) are associated with Amyotrophic Lateral Sclerosis (ALS).

Flashcard 10: The Golgi makes modifications to some amino acids trafficking through it. What are the modifications made to threonine?

Answer: O-oligosaccharide