Biology 9700 · AS & A Level · Respiration

Respiration — practice question

During glycolysis, glucose is broken down through a sequence of reactions to yield two pyruvate molecules. Fig. 6.1 shows the pathway of glycolysis.
(a(i))[1]

Using Fig. 6.1, identify the process taking place at steps 1 and 2.

(a(ii))[1]

Using Fig. 6.1, identify the process taking place at step 3.

(a(iii))[1]

Using Fig. 6.1, identify the process taking place at step 4.

(b)[2]

Explain why glucose has to be converted to hexose bisphosphate.

(c)[4]

Pyruvate can enter a mitochondrion when oxygen is present. Describe what occurs to pyruvate in a yeast cell when oxygen is not present.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: The process is phosphorylation.

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