Biochemistry exam 3 GlycolySis

What is the net ATP yield per glucose molecule at the end of the glycolytic pathway?

2

What are the three main products of glycolysis?

ATP; pyruvate; NAD⁺

Which of the following characterizes the conversion of glucose to lactate?

"Primed" by ATP phosphorylation

Aerobic pathway with no net oxidation

Located in the mitochondria

Net production of 4 ATP per glucose

Net production of 4 ATP per glucose

What is the net yield of the oxidation of 1 mole of glucose by anaerobic glycolysis?

2 moles of lactate and 2 moles of ATP

Which of the following products is formed when α-D-glucose reacts with ATP?

α-D-fructose-1-phosphate

α-D-glucose-1-phosphate

α-D-glucose-6-phosphate

α-D-fructose-6-phosphate

α-D-glucose-6-phosphate

Which of the following is a step in the phosphoglucoisomerase-catalyzed reaction on glucose-6-phosphate?

Creation of a carbonyl group at C-1

C-4 proton is removed

Opening of the pyranose ring

Removal of a furanose ring

Opening of the pyranose ring

Which of the following is NOT a characteristic of the phosphofructokinase-1 catalyzed reaction?

"Priming reaction"

Endergonic

"Valve" controlling the rate of glycolysis

Commits the cell to metabolize glucose

Endergonic

Which of the following substrate carbons is attacked by a cysteine –SH group during the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase, resulting in the formation of a hemithioacetal?

Acidic

Alpha

Amino

Carbonyl

Carbonyl

Which of the following enzymes catalyzes substrate-level phosphorylation during glycolysis?

Hexokinase

Phosphoglycerate Kinase

Phosphofructokinase

Glucokinase

Phosphoglycerate Kinase

Which of the following enzymes catalyzes the reaction 1,3-bisphosphoglycerate → 2,3-bisphosphoglycerate?

bisphosphoglycerate mutase

bisphosphoglycerate phosphatase

2,3-bisphosphoglycerate synthetase

1,3-bisphosphoglycerate hydrolase

bisphosphoglycerate mutase

Under anaerobic conditions, skeletal muscle generates lactate from pyruvate. Why does it do this?

To promote release of oxygen from hemoglobin

To lower the pH

To generate additional ATP

To regenerate NAD⁺ for further glycolysis

To regenerate NAD+ for further glycolysis

Which of the following two enzymes catalyze the two oxidation–reduction reactions in the fermentation of alcohol from glucose?

Alcohol Dehydrogenase and Pyruvate Decarboxylase

Glyceraldehyde-3-Phosphate Dehydrogenase and Alcohol Dehydrogenase

Lactate Dehydrogenase and Pyruvate Decarboxylase

Glyceraldehyde-3-Phosphate Dehydrogenase and Lactate Dehydrogenase

Glyceraldehyde-3-Phosphate Dehydrogenase and Alcohol Dehydrogenase

Under anaerobic conditions, skeletal muscle generates lactate from pyruvate. Why does it do this?

To promote release of oxygen from hemoglobin

To lower the pH

To generate additional ATP

To regenerate NAD⁺ for further glycolysis

To regenerate NAD+ for further glycolysis

Which of the following two enzymes catalyze the two oxidation–reduction reactions in the fermentation of alcohol from glucose?

Alcohol Dehydrogenase and Pyruvate Decarboxylase

Glyceraldehyde-3-Phosphate Dehydrogenase and Alcohol Dehydrogenase

Lactate Dehydrogenase and Pyruvate Decarboxylase

Glyceraldehyde-3-Phosphate Dehydrogenase and Lactate Dehydrogenase

Glyceraldehyde-3-Phosphate Dehydrogenase and Alcohol Dehydrogenase

What happens to lactate after it is produced by anaerobic muscle tissue?

It is carried by the blood to the liver for gluconeogenesis back to glycogen.

It is stored in muscle until oxygen is available.

It is further oxidized to acetate in muscle.

It is transferred to erythrocytes to release oxygen from hemoglobin.

It is carried by the blood to the liver for gluconeogenesis back to glycogen.

Which of the following enzymes catalyzes a reversible reaction that is an equilibrium-controlled step of glycolysis?

Aldolase

Pyruvate Kinase

Phosphofructokinase-1

Glucokinase

Pyruvate Kinase

Seven of the 10 reactions of glycolysis are reversible (ΔG near zero) and can be used in reverse of glycolysis for gluconeogenesis. Which enzymes catalyze the three irreversible reactions?

Enolase, Phosphoglycerate Kinase, Phosphofructokinase-1

Triose Phosphate Isomerase, Phosphoglycerate Mutase, Pyruvate Kinase

Phosphoglycerate Mutase, Phosphoglucoisomerase, Glyceraldehyde-3-Phosphate Dehydrogenase

Hexokinase, Phosphofructokinase-1, Pyruvate Kinase

Hexokinase, Phosphofructokinase-1, Pyruvate