Biology 9700 · AS & A Level · Respiration

Respiration — practice question

(a)[2]

ATP may be consumed or generated at different points during glucose respiration under aerobic conditions. Complete the table to indicate whether ATP is consumed or generated at each stage of respiration. Enter either YES or NO in each box.

(b)

An investigation was done to find out the effect of epicatechin on mitochondrial respiration in mice. Epicatechin is a naturally occurring substance found in cocoa beans and therefore present in chocolate. Two groups of mice, group $A$ and group $B$, took part in this investigation. Group $A$ received water with epicatechin added, twice a day for 15 days. Group $B$ received water without epicatechin, twice a day for 15 days. After 15 days, the structure of mitochondria from striated muscle cells in both groups of mice was studied. For each mouse, the surface area of the inner mitochondrial membrane was divided by the surface area of the outer membrane to give a ratio. Table 4.1 gives the mean ratios for the two groups of mice. The mice in group $A$ were able to exercise for longer than the mice in group $B$.

Worked solution & mark scheme

This 2-mark question has a full step-by-step worked solution and mark scheme. One marking point: glycolysis both uses ATP and produces ATP

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