Decomposition

• What should you be able to describe by the end of the video?

  Conditions required for decomposition
• What is meant by anaerobic decay?

  Decay that occurs without oxygen
• Who is the target audience for this video?

  Triple biology students
• What role do decomposing microorganisms play in the carbon cycle?

  They decompose waste and return carbon
• What do decomposers return to the soil?

  Mineral ions
• What is a compost heap and its purpose?

  • A compost heap is a pile of organic waste.
  • It decomposes plant material into compost.
  • Compost is used as a natural fertilizer.
• Why do gardeners add dead plant material to compost heaps?

  To allow decomposition and produce compost
• What is the first condition for rapid decomposition?

  Temperature
• How does temperature affect decomposition?

  Higher temperatures speed up enzyme activity
• What happens if the compost gets too hot?

  Enzymes can denature and decomposers die
• Why is moisture important for decomposition?

  Many chemical reactions require water
• What should gardeners avoid to maintain a compost heap?

  Allowing it to dry out
• What is the final important condition for decay?

  Amount of oxygen
• Why do decomposers need oxygen?

  To carry out aerobic respiration
• How do compost bins allow oxygen to enter?

  They have holes in the walls
• What do gardeners use to mix compost?

  A gardening fork
• What is the effect of mixing compost?

  Increases oxygen and surface area
• What occurs in the absence of oxygen during decay?

  Anaerobic decay takes place
• What gases are produced during anaerobic decay?

  Methane and biogas
• What are small-scale biogas generators used for?

  To provide fuel for homes
• What materials are often used in biogas generators?

  Food waste and animal manure
• Under what conditions do decomposers produce biogas?

  Anaerobic conditions
• What resources can students use to study decomposition?

  • Vision workbook
  • Online resources
  • Video lessons