GEOL2310 Chapter Seven
What is the main reservoir of nitrogen in the Earth?
The atmosphere (which contains 79% nitrogen).
Why nitrate is toxic for babies?
"Blue babies syndrome". Babies have more alkaline digestive tracts and E. coli (under the reducing conditions of the intestine) can reduce the nitrate to nitrite. Nitrite bonds to hemoglobin forming methemoglobin. Then the hemoglobin cannot take the oxygen to the cells in the body.
Explain ammonification.
Bacteria decompose amino acids and other organic molecules in dead animals and plants and convert them into nitrogen ammonium. Some plants can use ammonium but the rest can be stored in the soils and converted later to nitrate.
What are the effects of Nitrogen pollution in aquatic systems?
Bioestimulation Toxicity
In which parts of the body is phosphorous more concentrated?
Bones and teeth Fats?
What are the sources of energy for atmospheric, biological and industrial fixation?
Electricity Solar Energy Petroleum
Explain biological fixation.
Elemental nitrogen (N2) in the atmosphere is very unreactive because of the strong bond (three electron pairs) between the nitrogen atoms. Some bacteria (associated with leguminosae plants such as beans) and certain blue-green algae are able to fix nitrogen and assimilate it as organic nitrogen.
What is the reaction that occurs in industrial fixation.
Industrial fixation in plants that produce fertilizers. Under great pressure at 600o C, atmospheric nitrogen is combined with hydrogen to produce ammonia (NH3) that can be used as fertilizer.
What is the function of the ATP molecules that contain phosphorous?
Main source of energy
What nitrogen compounds are formed in the combustion of fossil fuels?
N2(g) + O2(g) == 2 NO(g) N2(g) + 2 O2(g) == 2 NO2(g)
What nitrogen compounds are used by plants?
NH3 Industrial fixation in plants that produce fertilizers. Under great pressure at 600o C, atmospheric nitrogen is combined with hydrogen to produce ammonia (NH3) that can be used as fertilizer.
What is the difference between nitrification and denitrification? Is one the exact opposite of the other?
Nitrification occurs when ammonia compounds produced during nitrogen fixation are converted to nitrites and nitrates by nitrifying bacteria. Denitrification occurs when denitrifying bacteria convert nitrates to gaseous nitrogen and nitrous oxides which return to the atmosphere. Eh
Why is the nitrogen cycle a biochemical cycle?
Nitrogen is converted from one form to another by organisms and for that reason the nitrogen cycle is referred to as a biochemical cycle. It is one of the most complex biochemical cycles.
Why is mountain building important in the phosphorous cycle?
Phosphorous in the rocks will be released if the rock is brought to the surface (by mountain building processes) and weathered. The whole process takes millions of years.
Why erosion is important in the phosphorous cycle?
Phosphorus moves in a cycle through rocks, water, soil and sediments and organisms. Over time, rain and weathering cause rocks to release phosphate ions and other minerals. ... Phosphorus in soil can end up in waterways and eventually oceans.
Why deforestation has an important impact in the phosphorous cycle?
The nutrients in the soil, including Phosphorus are washed away. The land becomes unfertile and the lack of nutrients causes animals to lose their habitat and go extinct. Scarcity of products found in the rainforest, driving up costs.
How is the velocity of the phosphorous cycle compared with the N cycle?
The phosphorous cycle is different from the nitrogen cycle because the major reservoir and source of P is the lithosphere (Earth's crust, minerals in solid sediments, soils, and rocks). The phosphorus cycle is a geological cycle because the inputs of P to the surface of the earth occur from erosion and weathering of phosphorous deposits.
Explain atmospheric fixation.
occurs when lighting converts N2 to nitrates and nitric acid.
