As a solute concentration rises, its rate of transport through a membrane increases up to the point where all the carriers are saturated. This point of saturation is called what

transport maximum

Explanation:

In the context of physiology, this point of saturation is called the transport maximum. Like mentioned, this is the point in which any further increase in the concentration of a substance no longer results in an increase in movement of that substance across a cell membrane, thus indicating that the carrier of that substance is completely saturated and can no longer complete its function.

radon is correct hope this