<prompt> Fischers lock and key theory postulates that:Active site in enzyme exists in proper conformation to the substrate molecule even in absence of substrateActive site during binding to substrate under goes conformational changes to fitThere is absolute specificity in reaction between enzyme and substrateEnzymes have catalytic power and accelerate reaction by reducing energy of activation  <response>: Ans. A. Active site in enzyme exists in proper conformation to the substrate molecule even in absence of substratea. Fischers lock and key theory for action of enzymes is also called rigid template model.b. The Fischers lock and key theory explains the specificity of enzyme substrate interactions-c. The Fischers model fails to explain the dynamic changes in the structure of enzyme that are required for catalysis.d. These are explained by the induced fit model given by Koshland. 