OxyFile #443

Biochemistry (Moscow), Vol. 61, No. 7, 1996, pp. 837-844.
Translated from Biochimiya, Vol. 61, No. 7, 1169-1181.

The Role of Electron Excited States in Biochemical Processes.
I.V. Baskakov, V.L.Voeikov 

Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, 
Miklukho-Maklaya 16/10, 117871, Moscow, Russia
Department of Bioorganic Chemistry, M.V.Lomonosov Moscow State


Oxidative processes major sources of energy accumulated in 
macroergic bonds of ATP. A part of the energy produced in redox 
reactions is transformed into the energy of electron excitation of 
the corresponding reaction products. Recently much experimental 
evidence has been obtained that confirms that the energy of 
electron excitation of such products may be used for high energy 
processes, photomodulation of enzyme activity, etc. The review 
describes some enzymatic and non-enzymatic biochemical processes 
generating electron excited states, potential pathways of 
radiation-less energy transduction, and examples of reactions 
coupled to these energy sources. The main attention is paid to 
triplet electron excited species because they are most probable 
participants of biochemical reactions. Numerous experimental data 
on "photobiochemistry without light" suggest that the processes 
generating electron excited states can be considered as one of the 
energy sources for certain cellilar biochemical reactions. 
Processes of photochemical coupling in the dark are compared with 
the electrochemical coupling that is the basis of cellular 
respiration. Unlike processes that use ATP as an energy source, 
photochemical coupling in the dark provides much more high energy.