The Carbon + Nitrogen Cycle Flashcards
…. fixed carbon atoms from carbon dioxide into organic compounds (e.g. glucose)
photosynthesis
… passes carbon atoms from organic compounds along food chains
feeding and animilation
… produces inorganic carbon dioxide from organic compounds as these are broken down to release …
respiration
energy
carbon from dead organic material is released during respiration by …
decomposers
… occurs when dead organic matter does not fully decay due to conditions in the soil, leading to fossil fuel formation
fossilisation
…. releases carbon dioxide into the atmosphere when fossil fuels are burned
combustion
what can plants and animals not fix from the air and soil directly
nitrogen
explain in the nitrogen cycle what this is: assimilation
plants get some of their nitrogen by absorption of nitrate ions via their roots
explain in the nitrogen cycle what this is: feeding
animals get all of their nitrogen (already assimilated into organic molecules e.g. protein) by feeding. on plants or other animals
explain in the nitrogen cycle what this is: ammonification
decomposition by decomposers of dead plant and animal material produces ammonia from organic compounds
explain in the nitrogen cycle what this is: nitrification
the ammonia is first oxidised to nitrate and then to nitrate by nitrifying bacteria
explain in the nitrogen cycle what this is: nitrogen fixation
free-living nitrogen-fixing bacteria in soil or symbiotic bacteria in root nodules can fix nitrogen from the air into ammonia which is then used by the bacteria or the symbiotic plant to make amino acids and proteins
explain in the nitrogen cycle what this is: denitrification
denitrifying bacteria use nitrate in the soil and convert it back into nitrogen
why do plants and animals need nitrogen
proteins, amino acids, DNA, ATP
what molecule in the atmosphere is nitrogen normally found in
nitrogen molecule
which organic molecules is nitrogen found in
proteins, amino acids, DNA, ATP
what inorganic molecules is nitrogen found in
NO2, ammonia, N2 in air + soil, NO3- nitrate in soil
what are 2 ways that atmospheric nitrogen gets into the ground
lightning (N fixation) + N fixing bacteria in root nodules
which organisms do nitrogen fixate for plants
N fixing bacteria in soil + denitrifying
why dont farmers have to put nitrogen fertiliser on soybeans
N fixing bacteria in root nodules
where do plant get their nitrogen from
air and soil
where do primary consumers get their nitrogen form
feeding on plants
where does an animals or plants nitrogen go when the animal or plant dies
decay into the soil, detritus
where do secondary consumers get their nitrogen from
nitrogen in animal proteins
which organisms convert ammonia into nitrate
nitrifying bacteria
how is nitrogen released into the atmosphere
denitrification
