Assertion (A): | Enzyme-catalyzed reactions proceed at rates vastly higher than that of uncatalyzed ones. |
Reason: | Enzymes require an optimum temperature and an optimum pH to work efficiently. |
1. | (A) is True but (R) is False. |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is False but (R) is True. |
4. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
1. | Enzymes generally function in a narrow range of temperature and pH. |
2. | Each enzyme shows its highest activity at a particular temperature and a pH called the optimum temperature and the optimum pH. |
3. | Activity declines both below and above the optimum value. |
4. | Low temperatures denature the enzyme; high temperatures temporarily inactivate the enzyme. |
Statement I: | Competitive inhibitor closely resembles the substrate in its molecular structure |
Statement II: | In spite of its close structural similarity with the substrate, the inhibitor does not compete with the substrate for the substrate-binding site of the enzyme. |
Statement III: | Inhibition of succinic dehydrogenase by succinate which closely resembles the substrate malonate in structure is an example of competitive inhibition. |
1. | Statement I is correct; Statement II is correct; Statement III is correct |
2. | Statement I is incorrect; Statement II is correct; Statement III is incorrect |
3. | Statement I is correct; Statement II is incorrect; Statement III is incorrect |
4. | Statement I is correct; Statement II is correct; Statement III is incorrect |
I: | form covalent bonds with side chains at the active site of the enzyme |
II: | form one or more covalent bonds with the substrate. |