Question 1: Define aerobic respiration and explain its importance during exercise.

Answer: Aerobic respiration is the process of releasing energy from glucose in the presence of oxygen, which provides sustained energy during exercise.

Question 2: Describe how the respiratory and circulatory systems work together during exercise.

Answer: The respiratory system supplies oxygen to the blood through the lungs, while the circulatory system transports oxygen-rich blood to muscles and removes carbon dioxide.

Question 3: What is the role of mitochondria in muscle cells during exercise?

Answer: Mitochondria produce ATP through respiration, providing energy for muscle contractions during exercise.

Question 1: Calculate the amount of energy (in kilojoules) released when 50 grams of glucose is completely oxidised during exercise. Use the formula: Energy (kJ) = mass of glucose (g) × energy released per gram (about 17 kJ/g).

Answer: 850

Question 1: Describe a safe way to measure the increase in breathing rate of students after running for 2 minutes. Include variables to control and safety precautions.

Answer: Students should measure their resting breathing rate, then run for 2 minutes while wearing suitable footwear and clothing. After running, they should immediately measure their breathing rate again. Variables to control include age, fitness level, and running intensity. Safety precautions involve warming up beforehand and avoiding overexertion.

Question 1: During intense exercise, a person's oxygen intake increases significantly. Explain why this occurs from a biological perspective and how it relates to industry applications such as fermentation or biofuel production.

Answer: During intense exercise, muscles require more energy, so the body increases oxygen intake to meet the higher demand for aerobic respiration in mitochondria. This ensures sustained ATP production. In industry, similar processes are used in fermentation and biofuel production, where oxygen levels influence the efficiency of energy-generating chemical reactions.

Question 1: Explain how increased respiration rates during exercise benefit muscle performance and how this understanding can be applied to improve industrial fermentation processes. (6 marks)

Answer: Increased respiration rates during exercise supply more ATP, which is necessary for sustained muscle contractions and performance. Enhanced oxygen uptake supports aerobic respiration, reducing fatigue. In industry, controlling oxygen levels in fermentation can optimise microbial activity and product yields, similar to how increased oxygen benefits muscles during exercise.

Question 1: Describe how understanding the body's response to exercise can help improve the design of industrial bioreactors used in bioethanol production.

Answer: Knowing how organisms increase respiration during activity helps optimise oxygen supply in bioreactors, improving microbial efficiency and bioethanol yield during fermentation.