CHEM237 Lecture 12: CHEM237-8-Ch11-12-Enzymes-annot.PDF
10 May 2016
School
Department
Course
Professor
Document Summary
Catalyzes the rxn in both directions, does not change keq but equilibrium is reached more quickly due to increased rates for both forward and reverse rxns. The effect of a catalyst on the transition state. Catalyzed rxns can be many orders of magnitude faster than uncatalyzed. Enzyme: protein that catalyzes (accelerates) a biochemical reaction (ribozyme = rna-based catalyst) Enzymes can bind specific substrates with high fidelity. Reaction occurs in an asymmetric pocket of the enzyme called the active site, which consists of: (i) binding site: aa which come in contact with substrate. Provide binding energy, and specificity (lock and key or induced fit) (ii) catalytic site: includes aa responsible for catalysis. Figure 13-1 an enzyme substrate complex illustrating both the geometric and the physical complementarity between enzymes and substrates. Cofactor: chemical compound that is bound (either tightly or loosely) to an enzyme and is required for catalysis e. g. metal, or organic, non-protein molecules.
