Neco Model Questions Vol1 2023 Biology Question 4

A practical investigation was carried out to study the effect of temperature on the rate of cellular respiration in baker's yeast. 5 g of dry yeast was suspended in 100 mL of 0.5 % glucose solution. The suspension was divided equally into three conical flasks and placed in water baths set at 20 °C, 30 °C and 40 °C respectively. Each flask was connected to an inverted graduated cylinder (capacity 250 mL) to collect the CO₂ released. The volume of gas collected was recorded every 5 min for a total period of 20 min. The data obtained are shown below. | Time (min) | CO₂ volume (mL) – 20 °C | CO₂ volume (mL) – 30 °C | CO₂ volume (mL) – 40 °C | |------------|------------------------|------------------------|------------------------| | 0 | 0 | 0 | 0 | | 5 | 12 | 28 | 45 | | 10 | 25 | 55 | 85 | | 15 | 35 | 78 | 115 | | 20 | 42 | 95 | 130 | Assume the gas behaves ideally and that the temperature of the gas in the cylinder remains equal to the water‑bath temperature.