Which of the following will not negatively affect the activity of an enzyme?
(a) Higher temperature than optimum
(b) Lower temperature than optimum
(c) Lower pH than optimum
(d) Presence of coenzyme

Options

A. Higher temperature than optimum
B. Lower temperature than optimum
C. Lower pH than optirmum
D. Presence of coenzyme

Answer

To solve the question "Which of the following will not negatively affect the activity of an enzyme?", we need to analyze each option provided:

1. **Option (a): Higher temperature than optimum**
- Enzymes have an optimal temperature at which they function best. If the temperature exceeds this optimum, the enzyme may denature, losing its shape and functionality. Therefore, a higher temperature than optimum will negatively affect enzyme activity.

2. **Option (b): Lower temperature than optimum**
- While lower temperatures can slow down the rate of enzyme activity, they do not typically denature the enzyme. However, they can reduce the kinetic energy of molecules, leading to slower reaction rates. Thus, lower temperatures can negatively affect enzyme activity but not as severely as higher temperatures.

3. **Option (c): Lower pH than optimum**
- Enzymes also have an optimal pH range. A lower pH than optimum can lead to denaturation of the enzyme or alter its active site, negatively affecting its activity. Therefore, this option negatively affects enzyme activity.

4. **Option (d): Presence of coenzyme**
- Coenzymes are non-protein molecules that assist enzymes in catalyzing reactions. They can enhance the activity of enzymes and are often necessary for the enzyme to function properly. The presence of a coenzyme does not negatively affect enzyme activity; in fact, it often positively influences it.

Based on the analysis, the correct answer is **(d) Presence of coenzyme**, as it does not negatively affect the activity of an enzyme.

### Summary of the Steps:
1. Identify the optimal conditions for enzyme activity (temperature and pH).
2. Analyze the impact of each option on enzyme activity.
3. Determine which option does not negatively affect enzyme activity.