• Cell respiration is the controlled release of energy from organic compounds to produce ATP.
• ATP from cell respiration is immediately available as a source of energy in the cell.
• Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.
• Skill: Analysis of results from experiments involving measurement of respiration rates in germinating seeds or invertebrates using a respirometer.
There are many simple respirometers which could be used. You are expected to know that an alkali is used to absorb CO2, so reductions in volume are due to oxygen use. Temperature should be kept constant to avoid volume changes due to temperature fluctuations.
• Anaerobic cell respiration gives a small yield of ATP from glucose.
• Application: Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking.
• Application: Lactate production in humans when anaerobic respiration is used to maximize the power of muscle contractions.
Design an experiment to investigate different sugars on the rate of respiration and fermentation.