Higher value of Km constant for an enzyme indicates

Options

A. Low affinity
B. How enzyme activity
C. High enzyme activity
D. Both(1) and (2)

Answer

To solve the question regarding the Km constant for an enzyme, we can break down the explanation step by step.

### Step-by-Step Solution:

1. **Understanding Km (Michaelis constant)**:
- Km, or Michaelis constant, is a key parameter in enzyme kinetics. It is defined as the substrate concentration at which the reaction rate is half of Vmax (maximum velocity).

2. **Relationship between Km and Enzyme Affinity**:
- The value of Km indicates the affinity of the enzyme for its substrate. A lower Km value suggests a higher affinity, meaning the enzyme can effectively bind to the substrate even at low concentrations. Conversely, a higher Km value indicates a lower affinity, meaning the enzyme requires a higher concentration of substrate to achieve half of Vmax.

3. **Interpreting a Higher Km Value**:
- When the Km value is high, it implies that the enzyme has a reduced ability to bind to the substrate. This means that the enzyme is less efficient in catalyzing the reaction at lower substrate concentrations.

4. **Conclusion**:
- Therefore, a higher value of Km indicates **low affinity** of the enzyme for its substrate.

### Final Answer:
A higher value of Km constant for an enzyme indicates **low affinity** for the substrate.

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