Chapter 4 Nutrient recycling Flashcards
Importance of nutrient recycling
Limited amount on earth so need to be recycled to prevent depletion
Definition of nutrient recycling
the way in which nutrients are exchanged between the biotic and abiotic parts of an ecosystem.
Importance of carbon cycle
forms carbohydrates, fats, proteins
Carbon cycle
Co2 - photosynthesis-plant carbohydrate-assimilated-animal carb-respiration-Co2 / die and decompose-fossil fuels-combustion-Co2
Role of plant in carbon cycle
remove by photosynthesis
release by respiration
Role of animal in carbon cycle
obtain by assimilation of plants
release by respiration
Role of decomposer in carbon cycle
release by decomposing dead organic matter
Importance of nitrogen cycle
needed for protein, DNA, RNA
Why can’t it be directly absorbed by plants?
78% of atmosphere nitrogen gas but not a usable form. Must be ‘fixed’ into nitrates before.
Function of nitrogen cycle
To fix into its usable form, nitrates
Nitrogen fixation def.
The fixing of nitrogen gas into its usable form nitrates
Anaerobic process
How is nitrogen fixed
Nitrogen fixing bacteria and lightning storms and car engines
Where are nitrogen fixing bacteria found
living in soil
living in nodules in roots of legume plants
Assimilation def.
The uptake and use of something.
Nitrogen cycle steps
(see notes)
Nitrogen gas fixed into nitrates, assimilated by plants and make plant protein. Assimilated by animals to make animal protein. Both plants and animals die and are decomposed into ammonia. Ammonia goes through nitrification by nitrifying bacteria and is converted to nitrites and then nitrates. Nitrates assimilated by plants. OR They go through denitrification by denitrifying bacteria and converted to nitrogen gas.
