Hydrogen peroxide is produced during the conversion of pyruvate to acetyl phosphate by the action of the enzyme ________.

Hydrogen peroxide is produced during the conversion of pyruvate to acetyl phosphate by the action of the enzyme ________.

• A. Lactate dehydrogenase
• B. Catalase
• C. Pyruvate oxidase (SpxB)
• D. Superoxide dismutase

Answer: (C)

In this pathway, hydrogen peroxide appears as a byproduct of oxidizing pyruvate to acetyl phosphate using oxygen. The enzyme that does this is pyruvate oxidase (SpxB), which catalyzes the reaction pyruvate + phosphate + O2 → acetyl phosphate + CO2 + H2O2. This oxidase uses oxygen to pull electrons from pyruvate, driving the formation of acetyl phosphate while releasing hydrogen peroxide. Lactate dehydrogenase would reduce pyruvate to lactate with no H2O2 produced, catalase breaks down H2O2 rather than creating it, and superoxide dismutase converts superoxide to H2O2 in a separate step. So the enzyme responsible for the hydrogen peroxide production in this conversion is pyruvate oxidase (SpxB).

In this pathway, hydrogen peroxide appears as a byproduct of oxidizing pyruvate to acetyl phosphate using oxygen. The enzyme that does this is pyruvate oxidase (SpxB), which catalyzes the reaction pyruvate + phosphate + O2 → acetyl phosphate + CO2 + H2O2. This oxidase uses oxygen to pull electrons from pyruvate, driving the formation of acetyl phosphate while releasing hydrogen peroxide. Lactate dehydrogenase would reduce pyruvate to lactate with no H2O2 produced, catalase breaks down H2O2 rather than creating it, and superoxide dismutase converts superoxide to H2O2 in a separate step. So the enzyme responsible for the hydrogen peroxide production in this conversion is pyruvate oxidase (SpxB).