Which statement defines activation energy?
it is the sum of the maximum energy and reactant energy.
it is the sum of the product energy and reactant energy.
it is the difference between reactant energy and maximum energy.
it is the difference between product energy and reactant energy.

Achemist at a pharmaceutical company is measuring equilibrium constants for reactions in which drug candidate molecules bind to a protein involved in cancer. the drug molecules bind the protein in a 1: 1 ratio to form a drug-protein complex. the protein concentration in aqueous solution at 25 ˚c is 1.74 x10-6 m . drug a is introduced into the protein solution at an initial concentration of 2.00 x10-6m. drug b is introduced into a separate, identical protein solution at an initial concentration of 2.00 x10-6m. at equilibrium, the drug a-protein solution has an a-protein complex concentration of 1.00 x10-6m, and the drug b solution has a b-protein complex concentration of 1.40 x10-6m. a. calculate the kc value for the a-protein binding reaction. b. calculate the kc value for the b-protein binding reaction. c. assuming that the drug that binds more strongly will be more effective, which drug is the better choice for further research?