When all the protein transporters are being used (saturation) then transport rate reaches at its

Answer

### Step-by-Step Solution:

1. **Understanding Protein Transporters**:
- Protein transporters are specialized proteins located in the cell membrane that facilitate the movement of molecules across the membrane. They can help transport substances either passively (without energy) or actively (requiring energy).

2. **Concept of Saturation**:
- Saturation occurs when all available protein transporters are occupied and cannot transport any more molecules. At this point, the transport rate cannot increase further, regardless of the concentration gradient.

3. **Active Transport Mechanism**:
- Active transport is the process where molecules move from an area of low concentration to an area of high concentration, which requires energy (usually in the form of ATP). This process is crucial for maintaining cellular functions.

4. **Graphical Representation**:
- To visualize the relationship between the number of protein transporters and the rate of transport, we can draw a graph. The x-axis represents the number of protein transporters, while the y-axis represents the rate of transport.
- As the number of transporters increases, the rate of transport also increases. However, once all transporters are saturated, the rate of transport levels off and reaches a maximum.

5. **Conclusion**:
- When all protein transporters are being used (saturation), the transport rate reaches its maximum. This means that no additional increase in transport can occur until some transporters become available again.

### Final Answer:
When all the protein transporters are being used (saturation), then the transport rate reaches its **maximum**.

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