Decomposition

• What is decomposition?

  Decomposition is the process of breaking down.
• Why is decomposition important?

  It prevents piles of dead stuff everywhere.
• What are the main contributors to decomposition?

  • Living things (produce waste)
  • Microorganisms (like soil bacteria and fungi)
• What happens when living things die or release waste?

  Decomposition returns elements to soil or air.
• Who primarily carries out decomposition?

  Microorganisms like bacteria and fungi.
• What factors affect the rate of decay?

  Temperature, water content, and oxygen availability.
• How does temperature influence decay rates?

  Warmer temperatures speed up enzyme-controlled reactions.
• What is the effect of high temperatures on enzymes?

  High temperatures denature enzymes.
• How does water content affect decay?

  Decay occurs faster in moist environments.
• What role does oxygen play in decomposition?

  Oxygen availability speeds up decomposition.
• How does the presence of oxygen affect microorganisms?

  Microorganisms need oxygen for aerobic respiration.
• What happens to decomposition rates in moist environments?

  Decay happens faster due to moisture.
• What are the three main factors affecting decay rates?

  1. Temperature
  2. Water content
  3. Oxygen availability
• What is the impact of high oxygen levels on decomposition?

  High oxygen levels accelerate the decay process.
• What is the relationship between oxygen and aerobic respiration?

  Aerobic respiration requires oxygen to occur.
• What methods can reduce the rate of decay in food preservation?

  • Refrigeration or freezing
  • Canning and sealing
  • Drying food
  • Adding salt or sugar
• How does storing food in a refrigerator affect decomposition?

  It slows down the decomposition rate.
• What is the effect of freezing food on microorganisms?

  Freezing kills or slows down microorganisms.
• How does canning food preserve it?

  Canning seals food to prevent microbial growth.
• What is the role of drying food in preservation?

  Drying removes moisture needed for decay.
• How does adding salt to food help in preservation?

  Salt draws out moisture and inhibits decay.
• What is the effect of sugar on food preservation?

  Sugar helps to inhibit microbial growth.
• What is the purpose of sterilization in this context?

  To kill any microorganisms present
• How is sterilization achieved according to the material?

  By exposing them to high pressure and temperature
• What does drying food remove that microorganisms need to survive?

  Water
• What effect does adding salt or sugar have on microorganisms?

  It causes them to lose water
• What are ideal conditions for composting?

  • Warm and moist conditions
  • Plenty of oxygen available
  • Organic matter like food waste
• What is compost made of?

  Decomposed organic matter
• How is compost used in gardening?

  As a fertilizer for crops and plants
• What conditions are necessary for quick compost production?

  Warm, moist, and oxygen-rich environment
• What is the role of compost bins in composting?

  They create ideal conditions for decomposition
• How can you increase oxygen availability in compost bins?

  By turning the compost regularly
• What is the average rate of decomposition in the first week?

  Measured in units of mould day⁻¹
• How do you calculate the average rate of decomposition?

  By dividing the amount of mould by days
• What should you do to find the change in decomposition rate?

  Subtract the lower rate from the higher rate
• What is the final answer for the average rate of decomposition?

  3.6 units of mould day⁻¹
• What should you do if asked to calculate the change in decomposition rate over different periods?

  Subtract the lower rate from the higher rate
• What is the significance of the mould graph?

  • Shows the amount of mould formed
  • Indicates the rate of decomposition
  • Helps in understanding composting efficiency
• What happens to cheese left out of the fridge?

  It forms mould
• What is the relationship between mould and decomposition?

  Mould helps decompose organic materials