Which is true regarding the mediated transport of a substance across a plasma membrane?
A)It depends upon the binding of that substance to a specific site on the membrane protein.
B)It depends upon movement of proteins from one side of the membrane to the other.
C)It always increases in direct proportion to the increasing concentration of the substance on one side of the membrane.
D)Both "depends upon the binding of that substance to a specific site on the membrane protein" and "depends upon movement of proteins from one side of the membrane to the other" are correct.
E)All of the choices are correct.

Question

Quizplus · Accepted Answer

Mediated transport requires a specific site on the membrane protein to which the substance can bind in order to be transported across the membrane. This is different from simple diffusion, which does not require any specific interaction with a protein. The transport rate of the substance may not always increase in direct proportion to its concentration on one side of the membrane.

Which Is True Regarding the Mediated Transport of a Substance