Glycolysis and Metabolism Quiz

What is "substrate level" phosphorylation?

Answer explanation

Substrate level phosphorylation is a metabolic process where a phosphate group is directly transferred from a substrate molecule to ADP, forming ATP. This occurs in glycolysis and the Krebs cycle, contrasting with oxidative phosphorylation.

What is the overall pathway in glycolysis?

Answer explanation

Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH. It consists of ten enzyme-catalyzed reactions, starting with glucose phosphorylation and ending with the formation of pyruvate.

How is the 6-carbon glucose converted to the 3-carbon glyceraldehyde-3-phosphate?

Answer explanation

Glucose undergoes glycolysis, where it is phosphorylated and split into two 3-carbon molecules, one of which is glyceraldehyde-3-phosphate (G3P). This process involves several enzymatic reactions and energy investment.

How is glyceraldehyde-3-phosphate converted to pyruvate?

Answer explanation

Glyceraldehyde-3-phosphate is converted to pyruvate through glycolysis, involving a series of enzymatic reactions that include phosphorylation, oxidation, and substrate-level phosphorylation, ultimately yielding pyruvate.

How is pyruvate metabolized anaerobically?

Answer explanation

Pyruvate is metabolized anaerobically through fermentation. In this process, it is converted into lactate in animals or ethanol and carbon dioxide in yeast, allowing for ATP production without oxygen.

Where are the control points in the glycolytic pathway?

Answer explanation

The control points in the glycolytic pathway are primarily at three key enzymes: hexokinase, phosphofructokinase-1 (PFK-1), and pyruvate kinase. These enzymes regulate the pathway's flow and energy production.

How much energy can be produced by glycolysis?

Answer explanation

Glycolysis produces a net gain of 2 ATP molecules and 2 NADH molecules per glucose molecule, yielding a total of about 7 ATP equivalents when considering NADH's contribution to the electron transport chain.

In glycolysis, glucose is converted to

Answer explanation

In glycolysis, glucose is converted to pyruvate. This process occurs in the cytoplasm and involves a series of enzymatic reactions that break down glucose to extract energy.

The NET result of a single glycolysis run is the formation of

• 2 NADH and 2 ATP

• 4 NADH and 2 ATP

• 2 NADH and 4 ATP

• 4 NADH and 4 ATP

Answer explanation

In glycolysis, the net gain is 2 NADH and 2 ATP. Although 4 ATP are produced, 2 ATP are consumed in the process, resulting in a net of 2 ATP. Therefore, the correct answer is 2 NADH and 2 ATP.

Under anaerobic conditions, the end-product of glycolysis is converted to?

• Lactic acid

• Ethanol

• Acetyl-CoA

• Glucose

Answer explanation

Under anaerobic conditions, glycolysis produces pyruvate, which is then converted to lactic acid in animals. This process regenerates NAD+, allowing glycolysis to continue, making lactic acid the correct answer.