What is a potential problem associated with facilitated diffusion?

The correct answer highlights a crucial aspect of facilitated diffusion, which involves the use of carrier proteins to transport solutes across cell membranes. When these carrier proteins become saturated, the rate of transport cannot increase further, even if concentrations of the solute on either side of the membrane continue to rise. This saturation leads to an accumulation of the solute on one side of the membrane because there are not enough available carrier proteins to facilitate its movement across the membrane.

Understanding this phenomenon is important in various physiological processes, such as glucose transport into cells, where excessive accumulation could lead to metabolic disturbances or affect cellular function. In this way, the saturation of carrier proteins represents a potential bottleneck in the efficiency of facilitated diffusion, significantly impacting homeostasis and cellular health. The presence of a maximum transport capacity is a key feature of this type of transport mechanism.