在需氧生物中,机体所摄取的氧基本上是作为呼吸链的电子终末受体,由细胞色素C氧化酶催化被还原成水,同时偶联ADP的磷酸化产生维持生命活动所需的高能化合物——ATP。氧分子O_2是一个三重态分子,其分子轨道上具有二个未配对电子,即它们的自旋方向相同(图1)。O_2与其它物质分子相互作用,它的反应活性是低的,这是因为受到自旋配对的限制。这就是说,O_2在氧化与之反应的原子或分子时要接受一对电子,而这一对 In aerobic organisms, the oxygen uptake by the body is essentially the electron-terminal receptor of the respiratory chain, which is catalyzed by cytochrome C oxidase to be reduced to water, while the phosphorylation of conjugated ADP produces the necessary life-sustaining activity High energy compound - ATP. Oxygen molecule O 2 is a triplet molecule with two unpaired electrons in its molecular orbit, ie, the same spin direction (Figure 1). O 2 interacts with other substance molecules and its reactivity is low because of the limitation of spin pairing. This means that O 2 accepts a pair of electrons when it oxidizes the atom or molecule with which it is reacting, and this pair