# Explain how the compartmentalisation provided by membrane-bound organelles allows eukaryotic cells to carry out multiple, potentially conflicting, biochemical processes simultaneously.

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

## Mark scheme (4 marks)

1. Membranes create separate internal compartments/microenvironments within the cell, isolating different biochemical reactions from one another.
2. Each compartment can maintain its own distinct conditions (e.g. pH, ion concentration, redox state) optimised for the enzymes/reactions it contains.
3. Potentially damaging/conflicting reactions are kept apart, preventing interference — for example, hydrolytic (digestive) enzymes in lysosomes are separated from the rest of the cytoplasm, preventing self-digestion.
4. Concentrating specific enzymes and substrates within a compartment increases the efficiency/rate of reactions, allowing multiple pathways to proceed concurrently without competition for substrates.

## Key terms

- [compartmentalisation](https://www.gradenine.co.uk/glossary/compartmentalisation)
- [membrane-bound organelle](https://www.gradenine.co.uk/glossary/membrane-bound-organelle)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-compartmentalisation-provided-by-8ae0d403) · Published by Druglandscape Ltd.