Decomposition

Question 1

Conditions needed for decomposition

Answer 1

• temperature
  = the warmer, the faster
  = decomposers use enzymes to break down plant materials
• amount of water
  = faster if compost moist
  = chemical reactions in decay require water
• amount of oxygen
  = decomposers carry out aerobic respiration
  = requires good supply of oxygen

Question 2

Why are compost heaps warm already

Answer 2

Decomposers release energy when they carry out aerobic respiration

Question 3

Importance of not being too hot

Answer 3

Otherwise enzymes in decomposers can denature and decomposers can die

Question 4

What happens if there’s no oxygen

Answer 4

Decomposing microorganisms carry out anaerobic decay
= produces mixture of gases eg methane
= called biogas

Question 5

Conditions for decay

Answer 5

• temp
• moisture
• oxygen

Question 6

How do plants produce chemicals

Answer 6

• co2 taken in by leaves in diffusion via stomata
• co2 used in photosynthesis to make glucose
• ions taken in by roots via active transport
• nitrate ions make amino acids
• phosphate make DNA

Question 7

How to maintain high concentration of bacterial reproduction

Answer 7

Increase temperature
Add more sugar
Add more oxygen
Stir culture
Remove toxins