5. In order to do certain spectroscopic experiments a single cysteine residue was introduced on to the larger of the two subunits and all other cysteines removed. The intention was to produce an enzyme that has been homogeneously covalently labelled on all the cysteines with a fluorescent reagent. One lab member plans to take a 20 MM stock of enzyme and react with 5 mM of the reagent for a few hours a and then remove the excess reagent by dialysis to obtain a fully labelled enzyme. Another lab member says it would be better to react, again for a few hours, the same amount of enzyme but with reagent at a concentration equimolar with the concentration of cysteine residues as that procedure would save losing expensive reagent in the dialysis step. Given that the second order rate constant for the reagent to react with a cysteine group is 40 M1 min which procedure would you adopt and why