Facilitated diffusion differs from simple diffusion because why?

• A. Facilitated diffusion requires energy to move substances across the membrane
• B. Facilitated diffusion requires a protein to move substances across the membrane
• C. Simple diffusion requires energy to move substances across a membrane
• D. . Simple diffusion requires a protein to move substances across the membrane

Answer: (B)

Verified step by step guidance

1. Understand the concept of diffusion: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. It is a passive process, meaning it does not require energy.
2. Differentiate between simple diffusion and facilitated diffusion: Simple diffusion occurs directly across the phospholipid bilayer without the need for any additional components. Facilitated diffusion, however, requires the assistance of specific proteins to transport substances across the cell membrane.
3. Identify the role of proteins in facilitated diffusion: In facilitated diffusion, transport proteins such as channel proteins or carrier proteins help move substances across the cell membrane. These proteins provide a pathway for certain molecules that cannot easily pass through the lipid bilayer.
4. Clarify the energy requirement: Both simple diffusion and facilitated diffusion are passive processes, meaning they do not require energy input from the cell. This is a key distinction from active transport, which does require energy.
5. Conclude with the correct statement: Facilitated diffusion differs from simple diffusion because it requires a protein to move substances across the membrane, whereas simple diffusion does not require such proteins.