Question

How do competitive and non competitive inhibitors affect enzyme function?

Answer 1

Hint: Enzymes are the proteins also known as biocatalyst. They affect the rate of the reaction. The molecule on which it binds is called the substrate and the substrate is converted into products. Inhibitors inhibit the formation of products.

Complete answer:
The enzymes have the active sites on its substrate to which the substrate attaches. The substrate binds at the active site and leads to the formation of enzyme substrate complex. Then the enzyme is released and the final product is formed. The enzymes only take part in the reaction but do not get used up. The shape of the enzyme is changed slightly on binding with substrate.
Enzyme inhibitors are the molecules which bind at the active site of the enzymes and inhibit the reaction (formation of enzyme substrate complex). There are two types of inhibition:

1)Competitive inhibitors: these inhibitors are similar in structure to that of the substrate. It competes for the same active site as that of the substrate. The inhibitors bind the active site and stop the substrate in binding. Thus the enzyme activity is declined due to the non formation of enzyme substrate complex.

2)Non-competitive inhibitors: These inhibitors bind at the different site of the enzyme and reduce the activity of the enzyme. Even if the substrate binds to the enzyme, the enzyme is no longer fit to catalyse the reaction as the inhibitor causes some changes in the enzyme. Thus the function of enzymes is made ineffective.

Note: The competitive and non-competitive inhibition is reversible. The reversible inhibitors do not cause any covalent modification in the enzyme structure. Whereas the irreversible inhibitors permanently affect the structure of enzyme and cause enzyme modification.