Question

Focus on one particular type of enzyme inhibitor, and address the following questions:

What enzyme does this inhibitor target?

Is it a competitive, non-competitive or irreversible inhibitor of that enzyme?

Is this inhibitor a poison or a drug?/what is it used for?

Do does an understanding of enzyme function help humans?

Answer 1

We will consider MALONATE in this question:

1. inhibition of succinic dehydrogenase by malonate which closely resembles the substrate succinate in structure.
2. When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor. Due to its close structural similarity with the substrate, the inhibitor competes with the substrate for the substrate- binding site of the enzyme. Consequently, the substrate cannot bind and as a result, the enzyme action declines. The reaction is reversible in nature.
3. It is a poison, decreases cellular respiration.

• uses: perfumes,  to synthesize other compounds such as barbiturates, artificial flavourings, vitamin B1, and vitamin B6.

4. Uses of knowing enzyme function:

• Knowing the chemical processes of the body. Eg.

CO2 + H2O -> H2CO3

In the absence of any enzyme this reaction is very slow, with about 200 molecules of H2CO3 being formed in an hour. However, by using the enzyme present within the cytoplasm called carbonic anhydrase, the reaction speeds dramatically with about 600,000 molecules being formed every second.

• Production of various drugs, pharmaceuticals, cosmetics, food etc.