(2)Double-Displacement(Ping-Pong)Reactions 乒乓反应机制 In double-displacement,or ping-pong,reactions,one or more products are released before all substrates bind the enzyme. 在所有底物结合到酶前，就有一个或多个产物时放出来。 The defining feature of double-displacement reactions is the existence of a substituted enzyme intermediate,in which the enzyme is temporarily modified. 存在酶修饰的中间体 S1 P1 S2 P2 Enzyme Enzyme E (E-NH3) (-NH)= (E-NH3) E (aspartate) (oxaloacetate) (ketoglutarate) (glutamate)(2)Double-Displacement (Ping-Pong) Reactions 乒乓反应机制 In double-displacement, or ping-pong, reactions, one or more products are released before all substrates bind the enzyme. 在所有底物结合到酶前，就有一个或多个产物时放出来。 The defining feature of double-displacement reactions is the existence of a substituted enzyme intermediate, in which the enzyme is temporarily modified. 存在酶修饰的中间体 S1 S2 P1 P2