Anyone understand the nitrogen cycle?:)
Sure, what do you need a hand with?
N2 makes up most of the air in our atmosphere, its unreactive and can't be used by plants in this form (N2 is also the gas they use in crisp packaging because food doesn't react with N2). Nitrogen fixation involves Legumes (peas) changing N2 into Nitrates (NO3), the plant can use NO3 as it is reactive.
Plants take in NO3 and use it to make their protein, this plant may (a) die or (b) eaten by an animal which uses it to make their protein (Note the passing on of Nitrogen atom or N). All living things will die and decay, decomposers take the Nitrogen atom from the bodies of living things and converts it to ammonia (NH3).
NH3 cannot be uses by plants as it is. Nitrification involves changing NH3 into Nitrites (NO2) and then finally to nitrates (NO3). Remember that plants can use NO3 so they are "happy".
Denitrification involves changing NO3 into N2 again. This is to restore the amount of N2 in the atmosphere, this is why it is called a cycle.
Hope this helped :)
Get the following into your description:
Atmospheric Nitrogen; Absorb; Plant Protein; Eaten; Animal Protein; Excretion; Decay.
Guaranteed to get at least half (if not all!) of the marks and much easier to remember.
Drawing a diagram of the cycle in you'r notes really helps to understand it