Which of these statements describes some aspect of facilitated diffusion?

• A. Facilitated diffusion is another name for osmosis.
• B. Facilitated diffusion of solutes occurs through phospholipid pores in the membrane.
• C. Facilitated diffusion requires energy to drive a concentration gradient.
• D. There is only one kind of protein pore for facilitated diffusion.
• E. Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

Answer: (E)

Verified step by step guidance

1. Facilitated diffusion is a type of passive transport, meaning it does not require energy input from the cell. It relies on the concentration gradient to move substances across the cell membrane.
2. Unlike simple diffusion, facilitated diffusion involves the use of specific proteins embedded in the cell membrane to help transport substances that cannot easily pass through the lipid bilayer.
3. These proteins can be either channel proteins or carrier proteins. Channel proteins form pores that allow specific molecules or ions to pass through, while carrier proteins bind to the substance and change shape to shuttle it across the membrane.
4. Facilitated diffusion is selective, meaning that each protein is specific to certain molecules or ions, allowing only those to pass through the membrane.
5. The statement 'Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane' correctly describes facilitated diffusion, as it highlights the role of these proteins in aiding the movement of solutes across the membrane.