Chapter 3.2: Respiration in Plants - Numerical Problems

Question 1: In aerobic respiration, one molecule of glucose is completely broken down. How many molecules of ATP are typically produced from this process?

Answer 1: In aerobic respiration, approximately 38 molecules of ATP are produced from one molecule of glucose.

Question 2: Compare the energy yield of aerobic respiration versus anaerobic respiration (alcoholic fermentation) from one molecule of glucose. What is the difference in ATP molecules produced?

Answer 2: Aerobic respiration yields approximately 38 ATP molecules per glucose molecule. Anaerobic respiration (alcoholic fermentation) yields only 2 ATP molecules per glucose molecule. The difference in ATP molecules produced is 38 - 2 = 36 ATP molecules.

Question 3: Write the balanced chemical equation for aerobic respiration, indicating the reactants and products.

Answer 3: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (38 ATP) (Glucose + Oxygen → Carbon Dioxide + Water + Energy)

Question 4: Write the balanced chemical equation for anaerobic respiration (alcoholic fermentation) in plants/yeast, indicating the reactants and products.

Answer 4: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy (2 ATP) (Glucose → Ethanol + Carbon Dioxide + Energy)

Question 5: If a plant cell needs to produce 76 molecules of ATP through aerobic respiration, how many glucose molecules would it need to break down?

Answer 5: Since 1 glucose molecule yields 38 ATP molecules in aerobic respiration: Number of glucose molecules = Total ATP needed / ATP per glucose molecule Number of glucose molecules = 76 ATP / 38 ATP/glucose = 2 glucose molecules.