Which of the following processes requires a carrier protein?

• A. Diffusion.
• B. Facilitated diffusion.
• C. Active transport.
• D. Endocytosis.
• E. b&c.

Answer: (E)

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 does not require energy or a carrier protein.
2. Learn about facilitated diffusion: Facilitated diffusion is similar to diffusion but involves the use of carrier proteins to transport molecules across the cell membrane. It does not require energy.
3. Explore active transport: Active transport is the movement of molecules against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process requires energy and a carrier protein.
4. Examine endocytosis: Endocytosis is a process where the cell membrane engulfs material to bring it into the cell. It does not require a carrier protein but involves the formation of vesicles.
5. Identify processes requiring carrier proteins: Facilitated diffusion and active transport both require carrier proteins to move substances across the cell membrane.