光合作用的总体平衡方程是:6 CO 2 + 6 H 2 O→C 6 H 12 O 6 + 6 O 2,其中二氧化碳和水反应产生葡萄糖和氧气。然而,总体反应并不表示化学反应或所涉及的分子的复杂性。植物和其他光合生物利用叶绿素吸收光(通常是太阳能)并将其转化为化学能。叶绿素强烈吸收蓝光和一些红光。它很难吸收绿色(反映它),这就是富含叶绿素的叶子和藻类呈绿色的原因。在植物中,叶绿素包围称为叶绿体的细胞器的类囊体膜中的光系统,叶绿体集中在植物的叶子中。叶绿素吸收光并利用共振能量转移激发光系统I和光系统II中的反应中心。当来自光子(光)的能量从光系统II的反应中心P680中的叶绿素中去除电子时,会发生这种情况。高能电子进入电子传输链。光系统的P700我使用光系统II,虽然这个叶绿素分子中的电子来源可以变化。进入电子传递链的电子用于将氢离子(H +)泵送到叶绿体的类囊体膜上。化学渗透势用于产生能量分子ATP并将NADP +还原为NADPH。反过来,NADPH用于将二氧化碳(CO2)还原成糖,例如葡萄糖。

澳洲南十字星大学Essay代写:叶绿素的定义及其在光合作用中的作用

The overall balanced equation for photosynthesis is: 6 CO2 + 6 H2O → C6H12O6 + 6 O2 where carbon dioxide and water react to produce glucose and oxygen. However, the overall reaction doesn’t indicate the complexity of the chemical reactions or the molecules that are involved. Plants and other photosynthetic organisms use chlorophyll to absorb light (usually solar energy) and convert it into chemical energy. Chlorophyll strongly absorbs blue light and also some red light. It poorly absorbs green (reflects it), which is why chlorophyll-rich leaves and algae appear green. In plants, chlorophyll surrounds photosystems in the thylakoid membrane of organelles called chloroplasts, which are concentrated in the leaves of plants. Chlorophyll absorbs light and uses resonance energy transfer to energize reaction centers in photosystem I and photosystem II. This happens when energy from a photon (light) removes an electron from chlorophyll in reaction center P680 of photosystem II. The high energy electron enters an electron transport chain. P700 of photosystem I works with photosystem II, although the source of electrons in this chlorophyll molecule can vary. Electrons that enter the electron transport chain are used to pump hydrogen ions (H+) across the thylakoid membrane of the chloroplast. The chemiosmotic potential is used to produce the energy molecule ATP and to reduce NADP+ to NADPH. NADPH, in turn, is used to reduce carbon dioxide (CO2) into sugars, such as glucose.

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