上降充通大学 SHANGHAI JIAO TONG UNIVERSITY Chapter 8: Enzymes:Basic Concepts and Kinetics 酶：基本概念及动力学 Berg·Tymoczko·Stryer Biochemistry Sixth Edition
Berg • Tymoczko • Stryer Biochemistry Sixth Edition Chapter 8: Enzymes: Basic Concepts and Kinetics 酶：基本概念及动力学
OUTLINES 1.Enzymes Are Powerful and Highly Specific Catalysts一概论 2.Free Energy Is a Useful Thermodynamic Function for Understanding Enzymes-热力学 3.Enzymes Accelerate Reactions by Facilitating the Formation of the Transition State一化学 4.The Michaelis-Menten Model Accounts for the Kinetic Properties of Many Enzymes一动力学 5.Enzymes Can Be Inhibited by Specific Molecules一抑制作用
1. Enzymes Are Powerful and Highly Specific Catalysts － 概论 2. Free Energy Is a Useful Thermodynamic Function for Understanding Enzymes －热力学 3. Enzymes Accelerate Reactions by Facilitating the Formation of the Transition State －化学 4. The Michaelis-Menten Model Accounts for the Kinetic Properties of Many Enzymes －动力学 5. Enzymes Can Be Inhibited by Specific Molecules －抑制作用 OUTLINES
The most striking characteristics of enzymes: 一 Catalytic power(催化高效性) Specificity(选择性) Chemical nature: 一Proteins蛋白质(Nearly all known enzymes are proteins,but proteins are not an absolute monopoly on catalysis);
The most striking characteristics of enzymes： － Catalytic power （催化高效性） － Specificity （选择性） Chemical nature: － Proteins 蛋白质 (Nearly all known enzymes are proteins, but proteins are not an absolute monopoly on catalysis);
Catalytic diversity Proteins as a class of macromolecules are highly effective catalysts for an enormous diversity of chemical reactions because of their capacity to specifically bind a very wide range of molecules. TABLE 8.8 Six major classes of enzymes Class Type of reaction Example Chapter 1.Oxidoreductases Oxidation-reduction Lactate dehydrogenase 16 2.Transferases Group transfer Nucleoside monophosphate 9 kinase(NMP kinase) 3.Hydrolases Hydrolysis reactions(transfer of Chymotrypsin 9 functional groups to water) 4.Lyases Addition or removal of groups Fumarase 17 to form double bonds 5.Isomerases Isomerization(intramolecular Triose phosphate isomerase 16 group transfer) 6.Ligases Ligation of two substrates Aminoacyl-tRNA synthetase 30 at the expense of ATP hydrolysis
Catalytic diversity Proteins as a class of macromolecules are highly effective catalysts for an enormous diversity of chemical reactions because of their capacity to specifically bind a very wide range of molecules
Active site活性中心 Active site活性中心：Catalysis takes place at a particular site on the enzyme. Substrate ES complex Enryme By untilizing the full repertoire of intermolecular forces 分子间作用力，enzymes bring substrates together in an optimal orientation定位，the prelude to making and breaking chemical bonds.They catalyze reactions by stabilizing transition states:过渡态，the highest-energy speciesi高能物质in reaction pathways
Active site 活性中心：Catalysis takes place at a particular site on the enzyme. By untilizing the full repertoire of intermolecular forces 分子间作用力, enzymes bring substrates together in an optimal orientation定位, the prelude to making and breaking chemical bonds. They catalyze reactions by stabilizing transition states过渡态, the highest-energy species高能物质 in reaction pathways. Active site 活性中心