Equal masses of potato tissue are supplied with the same amount of glucose in two sealed chambers. Chamber P contains oxygen. Chamber Q contains no oxygen and the tissue produces ethanol and carbon dioxide. The ATP yield in chamber Q is much lower than in chamber P.
Which explanation accounts for the difference in ATP yield?
In chamber Q, glucose is broken down incompletely, so most of its chemical energy remains in carbon dioxide.
In chamber P, oxygen provides the chemical energy that is transferred directly to the ATP molecules.
In chamber Q, glucose is broken down incompletely, so much of its chemical energy remains in ethanol.
In chamber Q, glucose is broken down completely, but ethanol prevents the ATP from releasing energy.
98 exam-style questions on Edexcel GCSE Biology 8.3 Respiration, covering 8.3.1 Aerobic and anaerobic respiration. Each one has a worked solution and a mark scheme showing where the marks go.