Which molecules need facilitated diffusion to move across the plasma membrane?
Charged molecules or ions require facilitated diffusion to move across the plasma membrane.
What is the main difference between simple and facilitated diffusion?
Simple diffusion does not require transport proteins, while facilitated diffusion requires transport proteins to move molecules across the membrane.
What type of molecules typically use simple diffusion?
Small uncharged molecules typically use simple diffusion to move across the cell membrane.
What role do transport proteins play in facilitated diffusion?
Transport proteins facilitate the movement of charged molecules or ions across the cell membrane in facilitated diffusion.
What are the two main types of transport proteins involved in facilitated diffusion?
The two main types of transport proteins are porins (channels) and transporters (carriers).
How do porins facilitate diffusion across the membrane?
Porins create membrane-spanning tunnels that allow molecules to pass directly through the membrane.
What is the function of aquaporins in facilitated diffusion?
Aquaporins specifically facilitate the transport of water molecules across the cell membrane.
How do transporters differ from porins in their mechanism of action?
Transporters do not form continuous tunnels; they open on one side of the membrane at a time and require conformational changes to transport molecules.
Why is no energy required for both simple and facilitated diffusion?
No energy is required because both processes involve the movement of molecules down their concentration gradients.
What type of molecules are typically transported by facilitated diffusion?
Facilitated diffusion typically transports ions or charged molecules across the cell membrane.