Where does glycolysis occur in cellular respiration

Glycolysis occurs in the cytoplasm of the cell during the first stage of cellular respiration.

Glycolysis means “splitting of glucose.” It is a biochemical process that breaks one molecule of glucose (a six-carbon sugar) into two molecules of pyruvate (three carbons each). This process releases a small amount of energy in the form of ATP.

Key Steps of Glycolysis

1. Glucose Activation: Glucose uses 2 ATP molecules to form fructose-1,6-bisphosphate.
2. Splitting Stage: The six-carbon compound splits into two three-carbon molecules (PGAL).
3. Energy Extraction: PGAL converts to pyruvate, producing ATP and NADH.

Overall Reaction

Glucose + 2NAD⁺ + 2ADP + 2Pᵢ → 2Pyruvate + 2NADH + 2ATP + 2H₂O

Location Significance

• Occurs in cytoplasm (outside mitochondria).
• Does not require oxygen (anaerobic step).
• Prepares pyruvate for further oxidation in mitochondria (Krebs cycle).