Redox State and Redox Environment in Biology

Cells and tissues must maintain a reducing environment to survive. This reducing environment provides the electrochemical gradient needed for electron flow. This movement of electrons provides the energy needed to build and maintain cellular structures and associated functions. An array of redox couples is responsible for the electron transfer. Some of these redox couples are linked to each other to form sets of related couples. Sets of couples can be independent from other sets if activation energies for reactions are high and there are no enzyme systems to link them kinetically. The redox environment of a cell is a reflection of the state of these couples. Bucher was the originator of studies that addressed cellular redox biochemistry. 1 His laboratory developed approaches to determine the states of various redox couples in cells and was the first to estimate the actual cellular reduction potentials for the NAD/NADH and NADP/NADPH couples.