Plant cells in pieces of fruit are respiring without oxygen. Ethanol is detected in the cells.
A student writes: 'The ethanol left in the cells shows why fermentation transfers only a small proportion of the chemical energy in glucose to ATP.'
Which is the best evaluation of this statement?
Incorrect, because ATP is stored inside ethanol until oxygen becomes available.
Incorrect, because glucose is broken down completely before the ethanol is formed.
Correct, because ethanol retains chemical energy that has not been transferred to ATP.
Correct, because ATP is converted into ethanol when oxygen is not available.
113 exam-style questions on OCR GCSE Biology 1.3 Respiration, covering 1.3.1 Cellular respiration supplies ATP, 1.3.2 Aerobic and anaerobic respiration, 1.3.3 Sugars and carbohydrates, 1.3.4 Amino acids and proteins, and 1.3.5 Fatty acids and lipids. Each one has a worked solution and a mark scheme showing where the marks go.