Explain why ATP is synthesised during respiration and outline what happens to ATP once it has been synthesised.

AQA A-Level Biology (7402) — 3.1.6 ATP · Explain and Outline · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

ATP is synthesised during respiration to store the energy released from glucose oxidation.

During cellular respiration the energy from glucose is transferred to ATP.

Once synthesised, ATP is hydrolysed to ADP and inorganic phosphate, releasing energy.

The released energy powers cellular processes such as muscle contraction, active transport and protein synthesis.

Examiner tips

Use the word "synthesised" and "hydrolysed" – examiners look for correct terminology.
Show the transfer of energy from glucose to ATP and then to cellular work.
Mention a specific cellular process to demonstrate understanding.
Keep the answer concise – 5 marks, so one sentence per point is sufficient.

Common mistakes

Using "produced" instead of "synthesised" for ATP.
Failing to state that ATP is broken down into ADP and inorganic phosphate.
Not linking the released energy to a specific cellular process.

Mark scheme (5 marks)

ATP is synthesised to provide / store energy (for the cell)
Respiration transfers energy (from glucose / food) to ATP
ATP is broken down / hydrolysed (releasing energy)
ATP is broken down into ADP and (inorganic) phosphate
The energy released from ATP is used to power cellular processes / named cellular process (e.g. muscle contraction, active transport, protein synthesis)

Key terms in this question

ATP · respiration