Klingenberg M
Ciba Found Symp. 1975(31):23-40. doi: 10.1002/9780470720134.ch3.
The energy transduction in mitochondria, with its principal agent ATP, still represents a major challenge for biological research. In general, the energy transduction process is divided into three sections: (1) the redox processes; (2) a conservation of intermediary energy forms; (3) synthesis of ATP. All three processes are linked to the membrane and are, therefore, as difficult to resolve as are processes linked to other biomembranes. It is probable that the electron transport system is constructed in such a way as to provide energy for synthesis of ATP and related processes. Important for this function is the transversal distribution of these components across the membrane, facilitating generation of membrane potential by electron or proton transfer. The exact composition of the respiratory chain is not yet known, in particular with respect to iron-sulphur proteins. Progress is achieved by defining single species of the respiratory chain, subunit composition, amino acid sequences and genetic derivation from intra- or extra-mitochondrial translation. Energy generated by oxidation can be trapped before ATP is formed by a number of reactions, in particular reversed electron transport, energy-dependent transhydrogenation and uptake of anions or cations into the mitochondria. The latter reaction is of major importance for understanding the intermediate energy form, as it appears to use energy most directly and be driven mainly by membrane potential or proton gradient across the membrane. The formation of ATP is a major problem hindering elucidation of the mechanism of oxidative phosphorylation. The mechanism of this enzymic process is not yet understood although the enzymes have been isolated and the subunits have been defined. Most probably, a concerted reaction between ADP and phosphate, driven by some conformational transition of the complex, leads to the formation of ATP. Release of ATP from a hydrophobic to hydrophilic environment may consume most of the energy.
线粒体中的能量转导，以其主要产物ATP为代表，仍然是生物学研究面临的一项重大挑战。一般来说，能量转导过程分为三个部分：（1）氧化还原过程；（2）中间能量形式的保存；（3）ATP的合成。所有这三个过程都与膜相关联，因此，与其他生物膜相关的过程一样难以解析。电子传递系统很可能是以一种为ATP合成及相关过程提供能量的方式构建的。这些组分在膜上的横向分布对这一功能很重要，有助于通过电子或质子转移产生膜电位。呼吸链的确切组成尚不清楚，尤其是关于铁硫蛋白。通过确定呼吸链的单一物种、亚基组成、氨基酸序列以及线粒体内或线粒体外翻译的遗传来源取得了进展。在ATP形成之前，氧化产生的能量可以通过一些反应捕获，特别是逆向电子传递、能量依赖性转氢作用以及阴离子或阳离子进入线粒体。后一种反应对于理解中间能量形式至关重要，因为它似乎最直接地利用能量，并且主要由跨膜的膜电位或质子梯度驱动。ATP的形成是阻碍阐明氧化磷酸化机制的一个主要问题。尽管已经分离出了这些酶并确定了亚基，但这个酶促过程的机制仍不清楚。很可能，由复合物的某种构象转变驱动的ADP和磷酸之间的协同反应导致了ATP的形成。ATP从疏水环境释放到亲水环境可能消耗大部分能量。
