Name an enzyme complex that helps detoxify reactive oxygen species in aerobes.

• A. Catalase
• B. DNA polymerase
• C. Catalase and superoxide dismutase
• D. Lactase

Answer: (C)

Reactive oxygen species are harmful byproducts of aerobic metabolism, so cells deploy antioxidant enzymes to keep them in check. Superoxide dismutase tackles the superoxide radical by converting it into hydrogen peroxide and oxygen. Catalase then rapidly breaks down hydrogen peroxide into water and oxygen. This two-step sequence provides coverage against the two common reactive species, forming a coordinated enzyme system that protects aerobes from oxidative damage. The other options don’t fit because DNA polymerase is involved in copying DNA, lactase digests lactose, and catalase alone handles hydrogen peroxide but leaves superoxide unchecked, so it doesn’t fully detoxify reactive oxygen species.