Question

Identify the type of transport across the cell membrane given below?

• A. Simple diffusion
• B. Facilitated diffusion
• C. Primary active transport
• D. Secondary active transport

Answer 1

The Correct Option is B

In the context of cell physiology, the transport of molecules across the cell membrane can occur via several mechanisms, each characterized by specific features:

• Simple Diffusion: This is a passive process where molecules move from an area of high concentration to low concentration without the need for a transport protein or energy input.
• Facilitated Diffusion: Like simple diffusion, this is a passive transport process where molecules move down their concentration gradient. However, it requires specific transmembrane proteins to aid the process, making it suitable for larger or charged molecules.
• Primary Active Transport: This active transport mechanism involves the movement of molecules against their concentration gradient, requiring the direct use of energy, often from ATP.
• Secondary Active Transport: This active process uses energy indirectly. It depends on the electrochemical gradient established by primary active transport.

In the provided question, the correct answer is Facilitated Diffusion. This is identified by the presence of specific transport proteins that assist molecules to cross the cell membrane without energy input, utilizing their concentration gradient.