Nutrient Cycles Flashcards
(33 cards)
What is an amino acid?
Monomer unit joined together to form a polypeptide
What are nucleotides?
Monomer unit joined together to form DNA or RNA
What are the stages of the nitrogen cycle?
Nitrogen fixation, nitrification, decay and ammonification, dentrification
What is nitrogen fixation?
Conversion of nitrogen gas into ammonium ions by free living nitrogen fixing bacteria found in the soil
What is nitrification?
Ammonium ions are converted to nitrates (NO2) then nitrates (NO3-) by nitrifying bacteria
What is decay and ammonification?
Breakdown of proteins found in decomposing material by saprobiont bacteria into amino acids. Amino acids are then converted to ammonium ions by ammonifying bacteria.
What is dentrification?
Conversion of nitrates (NO3-) into nitrigen gas which is released into air when dentrifying bacteria respire anaerobically.
How does lightening cause nitrogen fixation?
Lighteneing adds to the soil. Nitrogen and oxygen combine to make nitrogen oxides. Lightening breaks the triple bonds in nitrogen allowing oxygen to combine with it. Nitrogen oxides formed dissolve in rain forming nitrates.
How does bacteria cause nitrogen fixation?
Mutalistic bacteria are found in roots of leguminous plants. This is a mutalistic relationship where by bacteria provides the plant with nitrogen from air in return for carbohydrates.
What else causes nitrogen fixation?
Use if articificial fertilisers?
What is the nitrogen cycle?
Helps bring in the inert nitrogen from the air into the biochemical process in plants and then to animals. Plants need nitrogen to synthesise chlorophyll.
Why does the nitrogen cycle occur?
Atmospheric nitrogen cannot be used by most organisms and must be converted into a usable form
What are phospholipids used for?
Used to make cell membranes
What is the role of ATP?
It is hydrolysed to relsease energy
What is the phosphorus cycle?
Process by which phosphorus moves through the lithosphere, hydroshpere and biosphere
Why is the phosphorus cycle needed?
Phosphorus is essential for plant and animal growth as well as health of microbes inhabiting soil.
What are key stages in the phosphorus cycle?
Weathering, plant decay, feeding and digestion, waste products, decomposition, animal decay
How does weathering produce phosphorus?
PO4(3-) ions are in sedimentry rocks, weathering causes erosion of these rocks so phosphorus ions dissolve in rain water and go to bodies of water.
How does decomposition contribute to phosphorus cycle?
Other phosphorus ions from bones, shells, waste products and guano form sea birds decompose slowly and dissolve in water sorces, ending up in bodies of water
How does the death of animals contirbute to the phosphorus cycle?
Phosphorus ions are transferred to animals when they eat plants, when animals die, decomposers break down the animal body releasing phosphorus ions, this can end up in a body of water. Waste products of these animals can also decompose.
How does feeding and digestion contirbute to the phosphorus cycle?
Phosphorus ions are absorbed via plant roots via active transport, when animals eat these plants phosphorus ions are transferred to them.
How does soil and bodies of water contribute the phosphorus cycle?
Phosphorus ions from weathering, decomposing and decay end up in soil and bodies of water through these ions dissolving in rain, plants then absorb these ions through thier roots.
What is mycorrhizae?
Mutalistic associations between fungi and plant roots.
What is the function of fungi in a plant?
It is an extension of the root system.
