Exploring Cell Membrane Transport Mechanisms

The video tutorial explains how molecules enter and leave cells through the cell membrane. It covers diffusion, where molecules move from high to low concentration without energy, and facilitated diffusion, which uses protein channels. The tutorial also discusses active transport, requiring ATP to move molecules against the concentration gradient. Key examples include oxygen and carbon dioxide transport, and the role of aquaporins in water diffusion.

What is the primary function of the cell membrane?

• To produce energy

• To synthesize proteins

• To store genetic information

• To control the entry and exit of molecules

Which type of molecules can easily pass through the cell membrane by diffusion?

• Polar molecules

• Ions

• Large molecules

• Non-polar molecules

What is the direction of molecule movement in diffusion?

• From low concentration to high concentration

• In random directions

• From the nucleus to the cell membrane

• From high concentration to low concentration

Which of the following is an example of passive transport?

• Exocytosis

• Endocytosis

• Active transport

• Osmosis

Why does oxygen appear to always move into the cell?

• Because the mitochondria consume oxygen

• Because it is actively transported

• Because it is repelled by carbon dioxide

• Because it is produced inside the cell

What role do aquaporins play in the cell membrane?

• They facilitate the diffusion of water

• They synthesize proteins

• They store energy

• They transport ions

What is facilitated diffusion?

• Movement of molecules through the lipid bilayer

• Movement of molecules through a protein channel

• Movement of molecules using ATP

• Movement of molecules from low to high concentration

How does glucose enter the cell during facilitated diffusion?

• By attaching to a carrier protein

• By passing through the lipid bilayer

• By using ATP

• By osmosis

What is required for active transport to occur?

• ATP

• Oxygen

• A concentration gradient

• Water

Which type of transport moves molecules against the concentration gradient?

• Simple diffusion

• Osmosis

• Active transport

• Facilitated diffusion