BRAINCAKENutrient Cycles
Revision notes for Nutrient Cycles in AQA Biology (7402). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Nutrient CyclesEnergy flows through an ecosystem and is eventually lost as heat, but chemical elements such as carbon, nitrogen and phosphorus are recycled.
- Role of SaprobiontsSaprobionts (also called saprotrophs) are microorganisms, mainly bacteria and fungi, that obtain their nutrients from dead organic matter and from…
- The Nitrogen CycleNitrogen is needed to make amino acids (and so proteins) and nucleotides (DNA, RNA and ATP).
- Nitrogen FixationNitrogen fixation is the conversion of nitrogen gas (N2) from the atmosphere into ammonia (NH3), which forms ammonium ions (NH4+) in solution.
- AmmonificationAmmonification is the production of ammonia from organic nitrogen-containing compounds by saprobionts.
- NitrificationNitrification is the conversion of ammonium ions (NH4+) into nitrate ions (NO3−) by nitrifying bacteria.
- DenitrificationDenitrification is the conversion of nitrate ions (NO3−) in the soil into nitrogen gas (N2), which returns to the atmosphere.
- The Phosphorus CyclePhosphorus is needed by all organisms to make ATP, nucleic acids (DNA and RNA) and phospholipids in cell membranes.
- MycorrhizaeMycorrhizae are associations between certain fungi and the roots of plants.
- Natural and Artificial FertilisersIn a natural ecosystem, minerals taken up by plants are returned to the soil when organisms die or produce waste and saprobionts decompose them.
- Effects of Fertilisers on ProductivityProductivity is the rate at which plants produce biomass.
- LeachingLeaching is the process by which nutrients are removed from the soil.
- EutrophicationEutrophication is the process by which nutrients build up in a body of water, leading to an increase in the growth of algae and, eventually, the…
On the specification
- 3.5.4 Nutrient cycles