俏敏的生化PPT-华南师范大学.PPTVIP

enzyme 华南师范大学生命科学学院05级技术(2)班 刘俏敏 Enzyme’s name recommended name Systematic name substrate + reaction nature + enzyme (底物＋反应性质＋酶) 谷丙转氨酶(recommended name) 丙氨酸:а酮戊二酸基转移酶(systematic name) Enzyme classification Enzymes are grouped into six classes according to the type of reactions catalyzed Oxidoreductase (氧化-还原酶) Transferase (转移酶) Hydrolase (水解酶) Lyase (裂解酶) Isomerase (异构酶) Ligase (连接酶)  The four-digit number indicates the following Class (1-6) Sub-classes based on type of substrates Sub-sub classes based on cofactor type A unique number for each individual enzyme within a sub-sub-class EC+酶大类号．亚类号底物．亚亚类号．序号 eg: D-葡萄糖-6-磷酸磷酸水解酶 EC 3.1.3.9 Active center (active site) The active site of an enzyme is the place where all of the action occurs. It contains the functional groups (amino acid side chains) that bind the substrate (s) and catalyze It’s conversion to product (s) active site What does the active site do? The active site binds the substrates and positions them in the proper orientation for the reaction to occur The active site contains chemical groups that stabilize the transition state of the reaction The active site determines the specificity of the enzyme (i.e. it determines whether a particular substrate is bound and whether a particular product is made) Characteristics of active sites THE active site takes up a small part of the total volume of the enzyme The active site is 3-dimensional and is generally found in a crevice or cleft on the enzyme The active site displays highly specific substrate binding The active site is responsible for whether there is ordered or random binding of substrates and release of products Kinetics The velocity is affected by some factors 1) enzyme concentration 2) substrate concentration 3) temperature 4) pH 5) activator 6) inhibitor Affected by enzyme concentration when [S][E] V [E] Affected by substrate concentration 单底物酶促反应动力学