Question

What is denoted by X and Y in the given graph?

• A. X - Activation energy without enzyme, Y - Activation energy with enzyme
• B. X - Activation energy with enzyme, Y - Activation energy without enzyme
• C. X - Substrate concentration with enzyme, Y - Substrate concentration without enzyme
• D. X - Substrate concentration without enzyme, Y - Substrate concentration with enzyme

Answer 1

The correct option is B

X - Activation energy with enzyme, Y - Activation energy without enzyme

Most reactions do not start automatically because the reactions have an energy barrier which may be due to hydrogen bonding, the absence of precise collisions due to small reactive site, mutual repulsion etc.

External supply of energy needed to overcome this barrier is known as activation energy. Presence of an enzyme lowers the activation energy of the reaction and allows a large number of molecules to react at a time.