Question

Which of the following conditions are correct?

	Process	V max value	Km value
$\left(a\right)$	Competitive inhibition	Increases	Decreases
$\left(b\right)$	Non-competitive inhibition	Decreases	Remains same
$\left(c\right)$	Allosteric inhibition	Decreases	Increases
$\left(d\right)$	Un-competitive inhibition	Increases	Increases

• A. $\left(a\right)$
• B. $\left(b\right)$
• C. $\left(c\right)$
• D. $\left(d\right)$

Answer 1

Answer: (B)

Any substance that can diminish the velocity of an enzyme is known as an Inhibitor. The types of inhibition are Competitive, Non Competitive and Allosteric inhibition. In Competitive inhibition, the Enzyme and Inhibitor competes to bind to the same active site. Hence if substrate concentration is increased the chances of substrate binding to the enzyme will increase .Thus if (S) increases Km (Michaleis Constant) also increases. In non-competitive inhibition, the substrate and inhibitor binds at different sites hence do not compete with each other. This cannot be reversed by increasing the substrate concentration and hence Km remains constant. This velocity of reaction also decreases.