The shape of the curve obtained when substrate concentration is plotted against velocity of reaction

Options

A. Rectangular hyperbola
B. Bell shaped curve
C. Sigmoid curve
D. None of the above

Answer

To determine the shape of the curve obtained when substrate concentration is plotted against the velocity of a reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Variables**:
- The x-axis will represent the substrate concentration.
- The y-axis will represent the velocity (rate) of the reaction.

2. **Initial Reaction Phase**:
- At low substrate concentrations, as the concentration increases, the velocity of the reaction also increases. This is because there are many active sites available on the enzyme for the substrate to bind.

3. **Increasing Substrate Concentration**:
- As we continue to increase the substrate concentration, the velocity keeps increasing but at a decreasing rate. This is due to the fact that more active sites on the enzyme are being occupied, and there are fewer available sites for additional substrate.

4. **Saturation Point**:
- Eventually, a point is reached where all active sites of the enzyme are occupied. At this saturation point, the velocity of the reaction reaches its maximum (Vmax). Further increases in substrate concentration do not increase the velocity; instead, the velocity becomes constant.

5. **Shape of the Curve**:
- The resulting graph will exhibit a characteristic shape that resembles a bell curve. Initially, it rises steeply, then starts to plateau as it approaches Vmax, forming the upper part of the bell shape.

6. **Conclusion**:
- Therefore, the shape of the curve obtained when substrate concentration is plotted against the velocity of the reaction is a bell-shaped curve.

### Final Answer:
The shape of the curve is a **bell-shaped curve**.

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