a. Aerobic breakdown of glucose by the glycolytic pathway in muscles results in 2 molecules of pyruvate.
b. Aerobic breakdown of glucose by the glycolytic pathway in RBCs results in 2 molecules of pyruvate.
a. A = B
b. A < B
c. A > B
A>B
Which one of the following conversions in glycolysis leads to the most direct production of ATP by substrate-level phosphorylation?
a. 3 phosphoglycerate to phosphoenolpyruvate
b. glyceraldehyde 3 phosphate to 3 phosphoglycerate
c. dihydroxyacetone phosphate to glyceraldehydes 3 – phosphate
d. glucose to fructose 1 , 6 bisphophate
e. pyruvate to lactate
B ) glyceraldehyde 3 phosphate to 3 phosphoglycerate
In alcohol fermentation, the decarboxylation of pyruvate requires a coenzyme that contains the vitamin _____
thiamine.
What is substrate level phosphorylation?
a. Phosphorylation of AMP by ATP
b. ATP synthesis when the phosphate donor is a substrate with high phosphoryl transfer potential.
c. Phosphorylation of glycolytic intermediates
d. Phosphorylation of ATP coupled to an ion gradient
e. ATP and AMP synthesis from 2 molecules of ADP
B) ATP synthesis when the phosphate donor is a substrate with high phosphoryl transfer potential
The synthesis of glucose from pyruvate by gluconeogenesis:
D. requires the participation of biotin
Which one of the followng reactions is unique to gluconeogenesis (not found in glycolysis)?
B. pyruvate to oxaloacetate
Which of the following vitamins or coenzymes does NOT participate in the oxidative decarboxylation of pyruvate?
E. Biotin
What enzyme is responsible for the folowing reaction?
Pyruvate + CoA + NAD⁺ à acetyl CoA + NADH + H⁺ + CO₂
A. Pyruvate Dehydrogenase
Which one of the following conditions DECREASES the oxidation of acetyl CoA by the TCA cycle?
B. a low NADH concentration due to rapid oxidation to NAD⁺ through the respiratory chain
A 1-month-old baby showed abnormalities of the nervous system and
increased lactic acid in the blood. The total amount of pyruvate dehydrogenase and α-ketogluterate were
normal, but the total enzyme activity was reduced for both. Which ONE of the following statements concerning this baby is true?
C. The patient appears to have a thiamin deficiency
This Citric Acid Cycle enzyme is also part of an electron-transport complex _______________
succinate dehydrogenase.
During oxidative phophorylation, which one of the following reduces O₂ to H₂O?
E. cytochrome C oxidase
The enzyme complexes associated with oxidative phosphorylation and the
electron transport chain can be classified as _____________ proteins.
A. integral membrane
Which of the following would exist in the most oxidized state in mitochondria treated with antimycin?
E. Cytochrome oxidase
Glycerol-3-phosphate dehydrogenase, the enzyme responsible for the glycerol phosphate shuttle, exists in two isoforms. The cytosolic enzyme uses ________ as coenzyme, whereas the mitochondrial enzyme uses _______ as the coenzyme.
NAD⁺/NADH
FAD⁺/FADH₂
Phosphorylase b, the inactive enzyme, can be allosterically activated. What physiological conditions renders phosphorylase b back to the inactive state (R to T state)?
C. high ATP and glucose 6-phosphate levels
Calcium ion increase in the cytoplasm stimulates muscle contraction and therefore glycogenolysis. Calcium ion binds and leads to the activation of what enzyme in glycogen degradation?
E. Phosphorylase kinase
Which statement is true abut he reaction catalyzed by glycogen synthase?
B. It requires a primer of for to eight linked glucose residues.
Glycogen phosphorylase is _________(more, less) active when phosphorylated, and it is __________ (activated, inhibited) by glucose 6-phosphate