Page 7 Kinetic mechanisms Assume that a multisubstrate react

Page 7. Kinetic mechanisms. Assume that a multisubstrate reaction, A +B C+D,is catalyzed by enzyme E, and you wish to know the class of enzyme mechanism. Answer the following questions using the best choice(s) of the following three main classes. A correct answer may require you to choose more than one possible mechanism. 1. random sequential 2. ordered sequential in a) Which mechanism(s) would be consistent with data showing that the reaction proceeds through an enzyme ternary complex b) Which mechanism(s) would be consistent with data showing that C and D are released from the enzyme in no particular order. c) Which mechanism(s) would be consistent with data showing that the reaction involves a substituted enzyme intermediate d) Which mechanism(s) would be consistent with data showing that substrate A binds to the enzyme, then C comes off, then B binds, then D comes off

Solution

1 A enzyme through ternary complex proceed through order sequential.i.e in definite order and sequence.

2 substrate and product then released through random ways I.e no definite order.

3 substituted enzyme intermediate proceed through pinping-pong. mechanism I.e one or more product is released before all substrate get bind to enzyme.

Order reaction mechanism because of order ways of binding and release.