# Explain how the structure of the mitochondrion is related to its function in aerobic cellular respiration.

> IB DP Biology Standard Level (2023 syllabus) — B2.2 Organelles and compartmentalisation · Explain · 4 marks

## Mark scheme (4 marks)

1. The outer membrane encloses the organelle, creating a distinct internal compartment that separates the reactions of aerobic respiration from the cytoplasm.
2. The inner membrane is highly folded into cristae, which greatly increases the surface area available for the electron transport chain / oxidative phosphorylation / ATP synthase.
3. The intermembrane space (between the two membranes) allows a proton / H⁺ gradient to be established, which drives ATP synthesis via ATP synthase / chemiosmosis.
4. The matrix contains enzymes for the Krebs cycle / link reaction, and also contains mitochondrial DNA and ribosomes, allowing the organelle to produce some of its own proteins.

## Key terms

- [mitochondrion](https://www.gradenine.co.uk/glossary/mitochondrion)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-structure-of-the-27df34d0) · Published by Druglandscape Ltd.