decay Flashcards
(11 cards)
1
Q
what is compost?
A
decomposed organic matter used as a natural fertiliser for crops and garden plants
2
Q
what do gardeners and farmers do and why?
A
try to provide optimum conditions for rapid decay of waste biological material
3
Q
which animals are responsible decomposition?
A
- microorganisms such as bacteria, fungi
- detritus feeders
4
Q
describe the role of temperature in decay
A
- warmer temps make things decompose quicker because they increase the rate that enzymes involved in decomposition work at
- too hot, decomposition slows down or stops as they enzymes’ active site has changed shape due to bonds being broken, meaning the substrate no longer fits so it is denatured
- cold temps slow rate down as there is not enough energy
5
Q
describe the role of water availability in decay
A
decay takes place faster in moist environments because many of the chemical reactions in decay require water
6
Q
describe the role of oxygen availability in decay
A
- organisms need oxygen to respire, ultimately to survive
- more oxygen, faster microorganisms work
7
Q
what do decomposers do?
A
- return mineral ions back to the soil
- return carbon back to the atmosphere
8
Q
mixing compost
A
- break up large chunks, increasing surface area for decomposers to act on
- allows more oxygen to pass into centre
9
Q
what is decomposition?
A
the process by which dead organic matter is broken down into simpler substances
10
Q
what is decay?
A
the breakdown of organic matter by decomposers
11
Q
what happens if soil is waterlogged?
A
- rate of decay decreases
- water fills air gaps so less oxygen
- less aerobic respiration
- fewer chemical reactions so slower decomposition
