55.Which is NOT true about facilitated diffusion?a.It requires energy.b.It requires a carrier.c.It requires a concentration gradient.

To determine which statement about facilitated diffusion is NOT true, let's analyze each option:

1. Facilitated Diffusion and Energy Requirement:

   • Facilitated diffusion is a passive transport process that does not require energy (ATP) to move molecules across the cell membrane. Instead, it relies on the concentration gradient where molecules move from a region of higher concentration to a region of lower concentration. Therefore, statement a ("It requires energy.") is NOT true.

2. Facilitated Diffusion and Carrier Requirement:

   • This process often involves specific carrier proteins that assist in transporting substances that cannot freely cross the membrane. Thus, statement b ("It requires a carrier.") is true.

3. Facilitated Diffusion and Concentration Gradient:

   • As mentioned before, facilitated diffusion does require a concentration gradient for the movement of molecules from high to low concentration. Thus, statement c ("It requires a concentration gradient.") is true.

Final Answer

The statement that is NOT true about facilitated diffusion is: a. It requires energy.