Energy transfer in and between organisms - NITROGEN/PHOSPHOROUS CYCLE Flashcards
Give any examples of compounds containing nitrogen
DNA, RNA, proteins, ammonia
Give an example of assimilation
Primary consumer eating the producer
How is nitrogen in the DNA of a primary consumer converted to ammonia?
Decomposition by saprobionts
What is ammonification?
- Production of ammonia from organic nitrogen containing compounds
- Saprobionts feed on faeces and dead organisms materials releasing ammonia
- The ammonia is converted to ammonium ions in the soil
What is the process in which ammonium ions are converted to nitrites, and then nitrates?
Nitrification
- Also an oxidation reaction
What type of bacteria is required for nitrification?
Nitrifying bacteria (free living microorganisms in the soil)
How are nitrates transferred to the plants (producers)?
Active transport into roots
What is denitrification?
The process of converting nitrate ions in the soil to N2 gas in the atmosphere
What type of bacteria is required for denitrification?
Denitrifying bacteria
- Anaerobic
Why is it serious in agriculture if the soil is not aired, and how can farmers prevent it?
- Soil becomes waterlogged and has low oxygen concentrations
- More denitrifying bacteria
- Can be prevented by ploughing
How can farmers improve the concentration of soil nitrates?
Adding fertilisers
How can N2 in the atmosphere be converted to nitrate ions in the soil?
Free living nitrogen fixing bacteria
- Reduces gaseous nitrogen to ammonia
How does nitrogen fixation occur in plants?
Mutualistic nitrogen fixing bacteria in legumes
- Gives nitrogen to the plants
- Obtains carbohydrates from the plants
