Cell: Structure and Functions
Cell: The Unit of Life
One of the following does not support facilitated diffusion.
- It requires energy input.
- It is a passive process.
- Solutes are moved by a change in shape in the carrier protein.
- The solute can move in either direction.
Correct Answer: Option(a)
Solution: Facilitated transport is passage of substances along the concentration gradient without expenditure of energy that occurs with the help of special permeating proteins called as permeases.
Permeases form pathways for movement of certain substances without involving any expenditure of energy. Permeases change shape on binding of substances. The conformational changes in the shape of protein are actually responsible for movement of substances across the membranes through the facilitator proteins or permeases. Facilitated transport occurs in case of some sugars, amino acids and nucleotides.