This deep dive covers What is Decomposition? within Decomposition for GCSE Biology. Topic 4: Decomposition It is section 2 of 11 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 11
Practice
15 questions
Recall
20 flashcards
🔬 What is Decomposition?
Decomposition is the breakdown of dead organic material into simpler inorganic substances by the action of microorganisms. The main decomposers are bacteria and fungi, which use a method called saprotrophic nutrition:
- Decomposers secrete enzymes onto dead organic material outside their body
- Enzymes digest the material into small, soluble molecules
- The decomposer absorbs those soluble molecules as nutrients
Detritivores (e.g., earthworms, woodlice) assist decomposers by physically breaking dead material into smaller pieces, greatly increasing the surface area available for microbial enzyme action.
Decomposition is essential to all ecosystems — it returns mineral ions (such as nitrates) to the soil for plant uptake, and releases carbon dioxide back into the atmosphere. Without decomposition, nutrients would remain locked in dead organisms and the carbon cycle would stop.