Decomposition in Biology

Key Concepts

• Decomposition: The process by which decomposing microorganisms like bacteria and fungi break down waste materials and dead remains.
• Anaerobic Decay: Decomposition in the absence of oxygen, producing biogas which includes methane.

Importance of Decomposition

• Returns carbon to the atmosphere.
• Returns mineral ions to the soil, enriching it.
• Produces compost, used as a natural fertilizer rich in minerals for plant growth.

Optimal Conditions for Decomposition

1. Temperature

   • Decomposition is faster at warmer temperatures.
   • Decomposers use enzymes which work optimally in warm conditions.
   • Caution: Compost should not get too hot to prevent enzyme denaturation and decomposer death.
   • Compost heaps naturally warm due to energy release during aerobic respiration by decomposers.

2. Water

   • Moisture accelerates decomposition.
   • Necessary for chemical reactions involved in decay.
   • Important to keep compost moist to maintain efficient decomposition.

3. Oxygen

   • Essential for aerobic respiration in decomposers.
   • Compost bins often have holes for oxygen entry.
   • Regular mixing with a gardening fork can improve oxygen supply and break up clumps, increasing surface area.

Anaerobic Decay

• Occurs in the absence of oxygen.
• Produces biogas, which includes methane.
• Small-scale biogas generators use plant materials or animal manure.

Study Resources

• Vision workbook for questions and further study on decomposition.