An example of a biochemical reactant

2 Reactants and reactions in biochemistry 2.2.1 An example of a biochemical reactant 

In solutions of ionic strength of approximately 0.25 M, a hydrogen ion dissociates from HATP3- with an acid-base pK of approximately 6.47 [5], where pK is defined as — log10 Keq and Keq is the dissociation reaction equilibrium constant. The equilibrium expression is  

If we denote total ATP concentration [ATP] = [ATP4 ] + [HATP3 ] and assume that the system is in equilibrium, then 

2 For biochemical species we use the convention of indicated charge with a superscript number and sign. This way, even an uncharged species such as NADH0 is distinguished from the reactant NADH, which could be made up of several rapidly interconverting species. 

The denominator of Equation (2.11) is called the binding polynomial for reactant L and is denoted Pl([H+]). 

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