Glycolysis converts glucose to pyruvate with net production of ATP and NADH in which cellular compartment?

Glycolysis converts glucose to pyruvate with net production of ATP and NADH in which cellular compartment?

• A. Mitochondria
• B. Mitochondria and chloroplasts
• C. Cytosol
• D. Nucleus

Answer: (C)

Glycolysis happens in the cytosol—the fluid part of the cytoplasm inside the cell. All the enzymes that convert glucose to pyruvate operate in this location, so the whole pathway occurs there rather than in organelles like mitochondria or the nucleus. During glycolysis, a net amount of ATP is produced via substrate-level phosphorylation, and NAD+ is reduced to NADH. This setup makes cytosol the correct compartment because the subsequent steps of aerobic respiration—the pyruvate conversion to acetyl-CoA, the Krebs cycle, and oxidative phosphorylation—take place inside mitochondria, while the nucleus houses genetic material. Under aerobic conditions, pyruvate moves into mitochondria for further oxidation; under anaerobic conditions, the NADH produced must be reoxidized in the cytosol to keep glycolysis running.

Glycolysis happens in the cytosol—the fluid part of the cytoplasm inside the cell. All the enzymes that convert glucose to pyruvate operate in this location, so the whole pathway occurs there rather than in organelles like mitochondria or the nucleus. During glycolysis, a net amount of ATP is produced via substrate-level phosphorylation, and NAD+ is reduced to NADH. This setup makes cytosol the correct compartment because the subsequent steps of aerobic respiration—the pyruvate conversion to acetyl-CoA, the Krebs cycle, and oxidative phosphorylation—take place inside mitochondria, while the nucleus houses genetic material. Under aerobic conditions, pyruvate moves into mitochondria for further oxidation; under anaerobic conditions, the NADH produced must be reoxidized in the cytosol to keep glycolysis running.