MBB 222 Study Guide - Midterm Guide: Daniel E. Koshland Jr., Conformational Change, Activation Energy
Document Summary
Induced fit is a term that describes how substrate binding to enzymes is often associated with structural changes in the enzyme. These changes maximize the number of weak noncovalent interactions between the substrate and amino acid residues in the enzyme active site. Induced fit model: the substrate and active site are complementary in shape and chemical properties, but do not have an exact fit. Upon binding, both the active site and the substrate undergo a conformational change. The substrate is forced into a conformation approximating the transition state; the enzyme keeps the substrate under stress, which helps it to get to its product conformation (or back to its reactant conformation). Up until 1958, biochemists thought that the observed high specificity of enzyme- mediated catalysis was best explained by rigid physical and chemical complementarity between the reactant, usually referred to as the substrate, and the enzyme.