Membrane Transport Quiz

What type of molecules can freely pass across the phospholipid bilayer?

• Large, charged molecules

• Small, lipophilic molecules

• Polar molecules

• Ions

Which type of transport requires the expenditure of energy?

• Passive transport

• Simple diffusion

• Active transport

• Facilitated diffusion

What is the movement of water molecules across membranes by osmosis called?

• Active transport

• Facilitated diffusion

• Simple diffusion

• Osmosis

What is the role of channel proteins in membrane transport?

• They facilitate active transport

• They facilitate diffusion

• They block molecule passage

• They provide energy for transport

What happens to molecules during passive transport?

• They move from low to high concentration

• They require ATP to move

• They move from high to low concentration

• They require membrane proteins to move

What is the main characteristic of simple diffusion?

• It requires energy input.

• It involves the movement of large, polar molecules.

• It is the net movement of molecules from a region of higher concentration to lower concentration.

• It requires membrane proteins.

Which type of molecules typically use facilitated diffusion to cross the cell membrane?

• Small, non-polar molecules

• Large, polar molecules or ions

• Water molecules

• Lipid-soluble molecules

What role do channel proteins play in facilitated diffusion?

• They provide energy for the movement of molecules.

• They contain a hydrophilic pore to enable passage.

• They actively transport molecules against the gradient.

• They break down molecules for easier transport.

What is osmosis?

• The diffusion of ions across a membrane.

• The active transport of solutes.

• The diffusion of free water molecules across a semipermeable membrane.

• The movement of large molecules through a membrane.

What are aquaporins?

• Proteins that transport ions across the membrane.

• Integral proteins that function as selective water channels.

• Lipid molecules that facilitate diffusion.

• Enzymes that break down solutes.