What is the main difference between active transport and facilitated transport?

• A. Facilitated transport uses proteins, but active transport does not.
• B. Active transport uses ATP to power transport, but facilitated transport does not.
• C. Active transport occurs across the plasma membrane, but facilitated transport does not.
• D. Active transport moves a substance from higher concentration low concentration, while facilitated transport moves a substance from low concentration to high concentration.
• E. All of the above are differences between active and facilitated transport.

Answer: (B)

Verified step by step guidance

1. Begin by understanding the basic definitions of active transport and facilitated transport. Active transport is the movement of molecules across a cell membrane using energy, typically in the form of ATP, against their concentration gradient. Facilitated transport, also known as facilitated diffusion, is the passive movement of molecules across the cell membrane via transport proteins, without the use of energy, along their concentration gradient.
2. Identify the role of energy in both processes. Active transport requires energy input, usually from ATP, to move substances against their concentration gradient (from low to high concentration). Facilitated transport does not require energy as it moves substances along their concentration gradient (from high to low concentration).
3. Examine the involvement of transport proteins. Both active and facilitated transport involve transport proteins. However, in active transport, these proteins often act as pumps that require energy to function, while in facilitated transport, they act as channels or carriers that allow passive movement of molecules.
4. Consider the direction of movement relative to the concentration gradient. Active transport moves substances from areas of lower concentration to areas of higher concentration, which is against the gradient. Facilitated transport moves substances from areas of higher concentration to areas of lower concentration, which is along the gradient.
5. Summarize the key differences: Active transport uses energy (ATP), moves substances against the concentration gradient, and involves transport proteins that act as pumps. Facilitated transport does not use energy, moves substances along the concentration gradient, and involves transport proteins that act as channels or carriers.