Final answer:
The relationship between the rate of transport and concentration gradient in facilitated diffusion is characterized by an asymptote, indicating saturation when all transport proteins are bound to solute molecules.
Step-by-step explanation:
The relationship between the rate of transport (J) and concentration gradient in facilitated diffusion is often characterized by:
a. Asymptote (able to be saturated).
The rate of solute movement across a membrane is directly proportional to the number of transport proteins in the membrane. However, as the concentration gradient increases, the rate of transport will eventually reach a maximum and level off. This is because all of the transport proteins become saturated with solute molecules, and adding more solute does not increase the rate of transport further.