Biology 9700 · AS & A Level · Photosynthesis as an energy transfer process

Photosynthesis as an energy transfer process — practice question

Cyclic photophosphorylation and non-cyclic photophosphorylation take place in the light-dependent stage of photosynthesis.
(a)[3]

Outline how cyclic photophosphorylation differs from non-cyclic photophosphorylation.

(b)[4]

Complete the passage about the Calvin cycle by inserting the most suitable word or words. A molecule of ................................................ joins with a five-carbon molecule, ribulose bisphosphate (RuBP), with the reaction catalysed by the enzyme ................................................ . This reaction forms a six-carbon compound that divides into two molecules of the three-carbon compound, glycerate 3-phosphate (GP). ATP and ................................................ are used to change GP molecules into molecules of a three-carbon sugar, triose phosphate (TP). Some TP molecules are used to make ................................................, while the others are recycled to regenerate RuBP using ATP.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: photosystem I only compared with photosystems I and II

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