Question

QUESTION 28 Among the following statements concerning the enzymes, all correct answers An apoenzyme consists of a holoenzyme and a.coenzyme Enzymes are biological catalysts that do not affect the reaction equilibrium The rate of reaction depends on the pH The catalytic site is formed of an active site and binding sites The activation energy of the uncatalyzed reaction is greater than the activation energy of the catalyzed reaction QUESTION 29 Which of the following statements are corrects? When the substrate concentration is equal to KM, the reaction rate is half of its maximal value The value of KM is proportional to the concentration of the ES complex Inhibitors are molecules capable of decreasing the enzyme activity Uncompetitive inhibitors have no effect on Vmax

Answer 1

Q28.

1. Apo enzyme is an inactive enzyme. It needs a coenzyme to get activated. Apo ezyme and its coenzyme together is called a holoenzyme.

2. Enzymes do not change reaction equilibrium. They only reduces the activation energy of the reaction.

3. Lower the PH higher the reaction rate.

4. Active site of an enzyme is the region where substrate binds. Binding site and catalytic sites are two sites of active site of an enzyme. Substrates bind to Binding sites and the catalysts bind to catalytic site.

5.Activation energy of catalysed reaction is lower than that of uncatalysed reaction.

ANSWER : So, the statements which are correct are 2, 3 and 5.

Q29.

1. Michaelis constant,Km is the substrate concentration at which the reaction rate is half of its maximal value.

2. Km is independent of substrate concentration.

3. Inhibitors are capable of decreasing enzyme activity.

4. Uncompetitive inhibitors lowers Vmax.

ANSWER : So, Statements which are correct are 1 and 3.