Biogeochemical Cycles Flashcard

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What is the nitrogen cycle?

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The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. It involves nitrogen fixation, nitrification, denitrification, and ammonification, allowing nitrogen to move through the atmosphere, soil, and living organisms.

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What is nitrogen fixation?

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Nitrogen fixation is the process of converting atmospheric nitrogen (N2) into ammonia (NH3) or related compounds in soil, primarily carried out by certain bacteria.

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How do fertilizers affect the nitrogen cycle?

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Excessive use of fertilizers can lead to an imbalance in soil nitrogen levels, causing nutrient runoff into water bodies, which can result in eutrophication.

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What role do bacteria play in the nitrogen cycle?

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Bacteria are crucial in the nitrogen cycle as they perform nitrogen fixation, ammonification, and nitrification, helping to convert nitrogen into forms usable by plants.

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What is ammonification?

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Ammonification is the process by which organic nitrogen from dead organisms and waste is converted into ammonia by decomposer bacteria.

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What is nitrification?

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Nitrification is the process of converting ammonia into nitrites (NO2-) and then into nitrates (NO3-) by nitrifying bacteria, making nitrogen available to plants.

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What is denitrification?

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Denitrification is the process by which nitrates are reduced to nitrogen gas (N2) or nitrous oxide (N2O) by denitrifying bacteria, returning nitrogen to the atmosphere.

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What is the carbon cycle?

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The carbon cycle is the series of processes by which carbon compounds are interconverted in the environment, involving photosynthesis, respiration, decomposition, and combustion.

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How does photosynthesis contribute to the carbon cycle?

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During photosynthesis, plants absorb carbon dioxide (CO2) from the atmosphere and convert it into glucose, thus removing CO2 from the air.

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What is cellular respiration?

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Cellular respiration is the process by which organisms convert glucose and oxygen into energy, releasing carbon dioxide and water as byproducts.