This required practical covers Required Practical: Measuring Decomposition Rate within Decomposition for GCSE Biology. Topic 4: Decomposition It is section 4 of 12 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
🧪 Required Practical: Measuring Decomposition Rate
This practical investigates how temperature affects decomposition by measuring the time taken for lipase enzyme to break down the lipids in milk. A pH indicator (e.g., cresol red) changes colour as fatty acids are released, allowing the rate of decomposition to be timed at different temperatures.
Practice questions for Decomposition
Which organisms are the main decomposers?
Explain how temperature affects the rate of decomposition.
Quick recall flashcards
How do decomposers feed? (saprotrophic nutrition)
Decomposers use saprotrophic nutrition:
1. Secrete enzymes onto dead material (extracellular digestion)
2. Enzymes break down large molecules
3. Decomposer absorbs the small soluble products
What is decomposition and who carries it out?
Decomposition is the breakdown of dead organisms and waste into simpler substances.
Carried out by decomposers: mainly bacteria and fungi.
This releases nutrients back into the soil for plants to use.