Anaerobic Respiration Produces Lactic Acid in Humans

Steps:

• Recall that anaerobic respiration occurs without oxygen, using glucose as the main substrate.
• Identify the end product in human muscle cells during oxygen shortage: lactic acid fermentation.
• Compare options to key features: oxygen use, byproducts, and energy yield.
• Select the option matching the lactic acid byproduct.

Why C is correct:

• In humans, anaerobic respiration converts glucose to lactic acid via glycolysis, releasing energy without oxygen (formula: C6H12O6 → 2C3H6O3 + energy).

Why the others are wrong:

• A: Anaerobic respiration does not require oxygen; it happens when oxygen is unavailable.
• B: Carbon dioxide is a byproduct of aerobic respiration, not anaerobic in humans.
• D: Anaerobic respiration releases less energy (2 ATP) than aerobic (up to 38 ATP).

Final answer: C