Question

Regarding catalytic cycle of an enzyme action, select the correct sequential steps :
A. Substrate enzyme complex formation. 
B. Free enzyme ready to bind with another substrate. 
C. Release of products. 
D. Chemical bonds of the substrate broken. 
E. Substrate binding to active site. 
Choose the correct answer from the options given below :

• A. E, A, D, C, B
• B. A, E, B, D, C
• C. B, A, C, D, E
• D. E, D, C, B, A

Answer 1

The Correct Option is A

The catalytic cycle of an enzyme action involves a series of steps that allow the enzyme to interact with a substrate, facilitate a reaction, and release products. Below is the correct sequential order of these steps:

1. E. Substrate binding to active site: The substrate first binds to the active site of the enzyme. This interaction is specific and forms the basis of enzyme-substrate specificity.
2. A. Substrate enzyme complex formation: Once the substrate binds to the enzyme's active site, an enzyme-substrate complex is formed. This temporary complex is crucial for catalyzing the reaction.
3. D. Chemical bonds of the substrate broken: In this step, the enzyme facilitates the breaking of chemical bonds in the substrate, often lowering the activation energy required for the reaction.
4. C. Release of products: After the reaction occurs and the substrate is transformed, the reaction products are released from the enzyme.
5. B. Free enzyme ready to bind with another substrate: The enzyme is now in its original form and is free to bind with another substrate molecule, ready to catalyze a new reaction cycle.

Correct sequence: E, A, D, C, B

Answer 2

Sequence of Enzyme Action:

• E. Substrate binding to the active site occurs first.
• A. Substrate-enzyme complex formation follows after the substrate binds to the active site.
• D. Chemical bonds of the substrate are broken, leading to the formation of products.
• C. Release of products occurs next.
• B. Free enzyme is ready to bind with another substrate to complete the cycle.

Thus, the correct answer is (1) E, A, D, C, B.