[stads_29]

If the enzyme creatine kinase is assayed:
                      CK
creatine + ATP -----> Creatine-p +ADP
                     <----

               PK
ADP +PEP ---->ATP + pyruvate
              <----
                        LDH
Pyruvate +NADH ----->lactate +NAD^+
                       <-----

oxidation of NADH is monitered at 340nm (where NAD+ doesnt absorb) In a cell of path length 1cm the absorbance of a 1mM sol od NADH at 340nm is 6.22

If .02ml of a sol of creatine kinase (conc:.08mg/ml) is added at 25C to a 1ml of assay mixture, in a cell of path length 1cm. Decrease in absorbance at 340nm is .52 per min. Whats the activity of the Creatine kinase sol in umol substrate consumed per min per mg enzyme?