Site balance general form

This type of expression is generally available for each adsorbate in a serial catalytic cycle when a strongly rate-determining step has been assumed. When each A.=9JO, has been determined, we can find the coverages of all surface species by using the site balance relation in the following form ... 

The same is true for Cope rearrangements in general. Most substituents at C-1 and C-3 accelerate the reaction, and with more than one of them, their effects are cooperative. Substituents at C-2, however, shift the balance of the transition structure towards a biradical-like intermediate in which the new a bond is formed ahead of the old one breaking. Substituent effects at this site are not cooperative with substituent effects at C-l and C-3, because they change the nature of the transition structure rather than contribute to it in the same way. 

Electron transfer in proteins generally involves redox centers separated by long distances. The electronic interaction between redox sites is relatively weak and the transition state for the ET reaction must be formed many times before there is a successhil conversion from reactants to products the process is electronically nonadiabatic. A Eandau-Zener treatment of the reactant-product transition probability produces the familiar semiclassical expression for the rate of nonadiabatic electron transfer between a donor (D) and acceptor (A) held at fixed distance (equation 1). Biological electron flow over long distances with a relatively small release of free energy is possible because the protein fold creates a suitable balance between AG° and k as well as adequate electronic coupling between distant redox centers. 

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