翻訳と辞書 Words near each other ・ Nitrocefin ・ Nitrocellulose ・ Nitrocellulose slide ・ Nitrochlorobenzene ・ Nitrocyclohexane ・ Nitroethane ・ Nitroethylene ・ Nitrofen ・ Nitrofural ・ Nitrofuran ・ Nitrofurantoin ・ Nitrogen ・ Nitrogen acid ・ Nitrogen assimilation ・ Nitrogen balance ・ Nitrogen cycle ・ Nitrogen deficiency ・ Nitrogen dioxide ・ Nitrogen dioxide poisoning ・ Nitrogen fixation ・ Nitrogen fluoride ・ Nitrogen generator ・ Nitrogen inversion ・ Nitrogen laser ・ Nitrogen monofluoride ・ Nitrogen monohydride ・ Nitrogen monosulfide ・ Nitrogen mustard ・ Nitrogen narcosis ・ Nitrogen nutrition in the arbuscular mycorrhizal system Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Nitrogen cycle ： ウィキペディア英語版 Nitrogen cycle The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. This transformation can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is nitrogen, making it the largest pool of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle. ==Ecological function== Nitrogen is necessary for all known forms of life on Earth. It is a component in all amino acids, as it is incorporated into proteins, and is present in the bases that make up nucleic acids such as RNA and DNA. Nitrogen gas (N2) is the largest constituent of the Earth's atmosphere,〔Emsley, John (2011) ''Nature's Building Blocks: An A-Z Guide to the Elements,'' New York, NY: Oxford University Press. ISBN 978-0-19-960563-7 p. 360〕 but this form is relatively nonreactive and unusable by plants.〔Nitrogen: The Essential Element. Nancy M. Trumann and Keith S. Porter. Center for Environmental Research, Cornell Cooperative Extension〕 Chemical processing or natural fixation (through processes such as bacterial conversion—see rhizobium) are necessary to convert gaseous nitrogen into compounds such as nitrate or ammonia which can be used by plants. The abundance or scarcity of this "fixed" nitrogen (also known as reactive nitrogen) frequently limits plant growth in both managed and wild environments. The nitrogen cycle, like the carbon cycle, is an important part of every ecosystem. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nitrogen cycle」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.