Metabolism — Flashcards

Flashcard 1341: Homocystinuria can be caused by _____ deficiencies.

Answer: vitamin (B6, B9, or B12)

Extra: Classic homocystinuria is most commonly caused by an autosomal recessive deficiency of cystathionine beta-synthase (CBS). However, elevated homocysteine (and subsequent homocystinuria) can also be caused by deficiencies in B6 (pyridoxine), B9 (folate), or B12 (cobalamin).

Flashcard 1342: If methylmalonyl-CoA mutase is dysfunctional, _____ accumulates in the blood and urine

Answer: methylmalonic acid

Flashcard 1343: Which cellular organelle is responsible for catabolism of branched-chain fatty acids, amino acids, and ethanol?_____

Answer: Peroxisome

Flashcard 1344: In total, the TCA cycle produces _____ FADH2 per acetyl-CoA

Answer: 1

Flashcard 1345: What is the mode of inheritance of protein C or S deficiency?_____

Answer: Autosomal dominant

Flashcard 1346: A _____ enzyme adds inorganic phosphate onto a substrate without using ATP

Answer: phosphorylase

Flashcard 1347: _____ are produced, predominantly by the liver, when growth hormones act on target tissue

Answer: Somatomedins (IGFs)

Flashcard 1348: _____ facilitate dissociation of GDP so that GTP can bind more rapidly, increasing the rate of G protein activation

Answer: Guanine nucleotide releasing factors (GRFs)

Flashcard 1349: Which bidirectional insulin-independent transporter is found in the beta-islet cells, liver, kidney, and small intestine?_____

Answer: GLUT2

Flashcard 1350: What is the rate-limiting enzyme for glycogenolysis? _____

Answer: Glycogen phosphorylase