Which of the following statements regarding enzyme inhibition is correct?

1. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein

2. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme

3. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

4. Non-competitive inhibitors often bind to the enzyme irreversibly 

Select the option which is not correct with respect to enzyme action.

1. Substrate binds with enzyme as its active site

2. Addition of lot of succinate does not reverse the inhibition of succinic dehydogenase by malonate.

3. A non-competitive inhibitor binds the enzyme at a site distinct from that which binds the substrate

4. Malonate is a competitive inhibitor of succinic dehydrogenase

Which one of the following statement is incorrect ?

1. A competitive inhibitor reacts reversibly with the enzyme to form an enzyme-inhibitor.

2. In competitive inhibition the inhibitor molecule is not chemically changed by the

enzyme.

3. The competative inhibitor does not affect the rate of breakdown of the enzyme-

substrate complex.

4. The presence of the competitive inhibitor decreases the k_m of the enzyme for the

substrate.

A competive inhibitor of succinic dehydrogenase is

1. malonate                 

2. oxaloacetate

3. $\mathrm{\alpha }$-ketoglutarate       

4. malate

The inhibition of succinic dehydrogenase by malonate is an example of

1. competitive inhibition

2. non-competitive inhibition

3. allosteric modulation

4. none of the above

An example of the competitive inhibition of an enzyme is the inhibition of:

1. succinic dehydrogenase by malonic acid

2. cytochrome oxidase by cyanide

3. hexokinase by glucose -6-phosphate

4. carbonic anhydrase by carbondioxide

In competitive inhibition:

(1) Inhibitor resembles the substrate in molecular structure

(2) Competition between substrates and inhibitors to occupy active sites

(3) Binding the inhibitors to activities sites declines the enzyme action

(4) All are correct

The adjoining graph shows change in conc. of substrate on enzyme activity. Identify A, B and C:

A competitive inhibitor of succinic dehydrogenase is: