Which of the following statements regarding enzymes is true? Enzyme function is not dependent on the 3-D structure or confirmation of an enzyme. Allosteric inhibitors bind to the active site of enzymes, so that substrates cannot. Enzymes are not dependent on the physical and chemical environmental factors, such as pH or temperature. Enzymes increase the rate of a reaction by making the reaction more exergonic. O Enzymes increase the rate of a reaction by lowering the activation energy
The Correct Answer and Explanation is :
The correct answer is:
“Enzymes increase the rate of a reaction by lowering the activation energy.”
Explanation:
Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy, which is the energy barrier that must be overcome for a reaction to proceed. By reducing this barrier, enzymes allow reactions to occur more efficiently and at a faster rate without being consumed in the process.
Now, let’s analyze why the other statements are incorrect:
- “Enzyme function is not dependent on the 3-D structure or conformation of an enzyme.”
- This is incorrect because an enzyme’s function is highly dependent on its three-dimensional (3D) structure. The shape of the active site determines the enzyme’s specificity for its substrate. If the enzyme undergoes denaturation due to extreme heat or pH changes, its structure is altered, making it non-functional.
- “Allosteric inhibitors bind to the active site of enzymes so that substrates cannot.”
- This is incorrect because allosteric inhibitors do not bind to the active site. Instead, they bind to a different site (the allosteric site), which induces a conformational change in the enzyme that reduces its activity or prevents substrate binding.
- “Enzymes are not dependent on physical and chemical environmental factors, such as pH or temperature.”
- This is incorrect because enzymes are highly sensitive to their environment. Changes in temperature and pH can affect the enzyme’s shape and function. Extreme conditions can lead to enzyme denaturation, making them ineffective.
- “Enzymes increase the rate of a reaction by making the reaction more exergonic.”
- This is incorrect because enzymes do not change the overall energy balance (ΔG) of a reaction. They only speed up the reaction by providing an alternative pathway with a lower activation energy.
In summary, enzymes are crucial biological catalysts that speed up reactions by lowering the activation energy, ensuring vital biochemical processes occur efficiently within living organisms.