Water Cycle In Biology

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Cycles in biology A cycle is a series of events repeated in the same order. Cycles are a major aspect of biology which occurs in a ecosystem, plants and animals. One cycle which is part of the ecosystem is the water cycle. The sun heats water in oceans and seas and water evaporates as water vapour into the air. Transpiration removes water from plants and soil. Air currents take water vapour into the atmosphere where cooler temperature causes it to condense into clouds. Air currents move water around the globe; cloud particles collide and fall out of the sky as snow, hail or sleet. Most water falls back into ocean or on land as rain where the water flows over ground as runoff. Some of runoff enters rivers flowing water towards ocean where water cycle had started. Another cycle which is part of the ecosystem is the nitrogen cycle. All living organisms require a source of nitrogen from which to manufacture proteins, nucleic acids and other nitrogen containing compounds. Plants take up most of nitrogen they need in form of nitrate (NO3- ) ions from the soil. Ammonification is the production of ammonia from organic compounds such as urea.…show more content…
CO2 from the atmosphere diffuses into the leaf through the stomata into the stroma of the chloroplast. In the stroma, the CO2 combines with a 5-carbon compound ribulose bisphosphate (RUBP). Combination of CO2 and RUBP produces two molecules of the 3-carbon glycerate-3-phosphate (GP). ATP and reduced NADP from light dependent reaction are used to reduce activated glycerate -3 -phosphate to triose phosphate (TP). NADP is reformed and goes back to light dependent reaction to be reduced again by accepting more H+ ions. Most triose phosphate molecules are used to regenerate ribulose bisphosphate using ATP from light dependent reaction. This is cyclic as RUBP is reformed to combine with a new CO2
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