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 are actively pumped across the membrane

What is the net movement of molecules from a region of higher concentration to lower concentration called?

• Active transport

• Simple diffusion

• Facilitated diffusion

• Osmosis

Which type of molecules can freely cross the plasma membrane without impediment during simple diffusion?

• Large, polar molecules

• Ions

• Small or non-polar molecules

• Proteins

What is the role of channel proteins in facilitated diffusion?

• They actively transport molecules across the membrane.

• They contain a hydrophilic pore to enable passage.

• They break down molecules for easier transport.

• They store energy for cellular processes.

What is the term for the diffusion of water molecules across a semipermeable membrane?

• Active transport

• Simple diffusion

• Osmosis

• Facilitated diffusion

What are aquaporins?

• Proteins that transport ions

• Selective water channels in cell membranes

• Enzymes that break down water

• Lipids that store water