Which statement best describes glycolysis?

Which statement best describes glycolysis?

• A. Glycolysis uses oxygen to split glucose.
• B. Glucose is converted into pyruvate and energy stored in ATP bonds are released.
• C. Pyruvate is converted into acetyl-CoA in mitochondria.
• D. Oxygen is required for electron transport.

Answer: (B)

Glycolysis is the first step of cellular respiration that breaks one glucose molecule into two pyruvate molecules in the cytoplasm. It does not require oxygen, so it can occur with or without oxygen. During glycolysis, energy is captured as ATP through substrate-level phosphorylation, giving a net gain of two ATP per glucose, and two NADH molecules are produced for later use. The key point is that glycolysis converts glucose into pyruvate and releases energy stored in ATP bonds. Other statements refer to later stages or oxygen-requiring steps: the conversion of pyruvate to acetyl-CoA happens in mitochondria after glycolysis, and oxygen is needed for the electron transport chain, not glycolysis.

Glycolysis is the first step of cellular respiration that breaks one glucose molecule into two pyruvate molecules in the cytoplasm. It does not require oxygen, so it can occur with or without oxygen. During glycolysis, energy is captured as ATP through substrate-level phosphorylation, giving a net gain of two ATP per glucose, and two NADH molecules are produced for later use. The key point is that glycolysis converts glucose into pyruvate and releases energy stored in ATP bonds.

Other statements refer to later stages or oxygen-requiring steps: the conversion of pyruvate to acetyl-CoA happens in mitochondria after glycolysis, and oxygen is needed for the electron transport chain, not glycolysis.