Producers, consumers, and decomposers use the chemical energy stored in glucose and other organic compounds to fuel their life processes. In most cells this energy is released by aerobic respiration, which uses oxygen to convert glucose (or other organic nutrient molecules) back into carbon dioxide and water. The net effect of the hundreds of steps in this complex process is represented by the following reaction.
Glucose + oxygen carbon dioxide + water + energy
C6H12O6 + 6O2 6CO2 + 6H2O + energy
Although the detailed steps differ, the net chemical change for aerobic respiration is the opposite of that for photosynthesis.
Some decomposers get the energy they used by breaking down glucose (or other organic compounds) in the absence of oxygen. This form of cellular respiration is called anaerobic respiration, or fermentation. The end products of this process are compounds such as methane gas (CH4), ethyl alcohol (C6H12O), acetic acid (C2H4O2,
the key component of vinegar), and hydrogen sulfide ( H2S, when sulfur compounds are broken down). Note that all organisms get their energy from anaerobic respiration, but only plants carry out photosynthesis.
生產者,消費者和分解者使用儲存在葡萄糖和其他有機化合物之化學能,添加燃料於其生命過程。在大多數細胞的能量被釋放的有氧呼吸中,將氧氣轉換葡萄糖(或其他有機營養分子)到二氧化碳和水。在這個數以百計的步驟的過程中之淨影響,是由以下反應。
葡萄糖+氧二氧化碳+水+能量
C6H12O6 + 6O2 6CO2 + 6H2O +能源
雖然不同的詳細步驟,但對於光合作用之淨化學變化的有氧呼吸是相反的。
在沒有氧氣下,有些分解得到他們所使用的能源打破葡萄糖(或其他有機化合物)。這種形式的細胞呼吸被稱為無氧呼吸,或發酵。最終產品的這一進程的化合物,如甲烷氣體(甲烷) ,乙醇( C6H12O ) ,乙酸( C2H4O2 ,
的重要組成部分,醋)和硫化氫( H2S ,當含硫化合物被細分) 。請注意,所有生物體均能獲得能量無氧呼吸,但只植物進行光合作用。
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