Cell Membrane Transport Quiz

What type of molecules can freely pass across the phospholipid bilayer without additional assistance?

• Large, charged molecules

• Small, lipophilic molecules

• Polar molecules

• Ions

Which of the following is true about passive transport?

• It requires ATP

• It moves substances from low to high concentration

• It involves movement along a concentration gradient

• It requires membrane proteins

What is required for active transport to occur?

• No energy

• ATP hydrolysis

• Movement along a concentration gradient

• Simple diffusion

Which process involves the movement of water molecules across membranes?

• Active transport

• Facilitated diffusion

• Osmosis

• Simple diffusion

What determines the type of passive transport used by a molecule?

• The size of the molecule

• The permeability of the molecule

• The charge of the molecule

• The concentration of the molecule

What type of molecules can freely cross the plasma membrane through simple diffusion?

• Large, polar molecules

• Small, non-polar molecules

• Ions

• Proteins

What is the role of channel proteins in facilitated diffusion?

• They provide energy for active transport

• They contain a hydrophilic pore to enable passage

• They break down molecules for easier transport

• They store molecules for later use

What is osmosis?

• The active transport of ions

• The diffusion of free water molecules

• The movement of proteins across a membrane

• The breakdown of solutes in water

What is a hypertonic solution?

• A solution with high solute levels and high free water

• A solution with low solute levels and high free water

• A solution with high solute levels and low free water

• A solution with equal solute and water levels

What are aquaporins?

• Proteins that transport ions

• Selective water channels in cell membranes

• Enzymes that break down solutes

• Lipids that store energy