Exploring Passive Transport Mechanisms

The video tutorial covers passive transport, focusing on diffusion, osmosis, and facilitated diffusion. It explains how molecules move across cell membranes without energy, from high to low concentration, achieving equilibrium. Diffusion is illustrated with examples like oxygen and carbon dioxide exchange in cells. Osmosis is discussed with scenarios involving distilled and salt water, highlighting hypertonic and hypotonic solutions. Facilitated diffusion is explained as a process where larger molecules and ions use protein channels to cross membranes without energy.

What is passive transport?

• Movement of molecules using protein channels

• Movement of molecules from low to high concentration

• Movement of molecules across a membrane without using energy

• Movement of molecules across a membrane using energy

Which scenario shows a greater concentration gradient?

• Scenario A with 8 dots on the left and 2 on the right

• Neither scenario shows a concentration gradient

• Both scenarios have the same concentration gradient

• Scenario B with 6 dots on the left and 4 on the right

What is the main characteristic of diffusion?

• Movement of water molecules only

• Movement of molecules from high to low concentration

• Movement of molecules from low to high concentration

• Movement of molecules using energy

How do cells obtain needed molecules through diffusion?

• By using protein channels

• By moving molecules from high to low concentration

• By using energy to transport molecules

• By moving molecules from low to high concentration

What happens to oxygen when it enters the lungs?

• It diffuses into the alveoli

• It diffuses into the capillaries

• It exits the body immediately

• It stays in the trachea

What is osmosis?

• Movement of solutes from low to high concentration

• Movement of solutes from high to low concentration

• Diffusion of water from high to low concentration

• Diffusion of water from low to high concentration

What happens to a cell placed in distilled water?

• It dissolves

• It shrinks

• It remains the same

• It swells

In a hypertonic solution, what happens to a cell?

• It loses water

• It gains water

• It dissolves

• It remains the same

What does facilitated diffusion require?

• Movement from low to high concentration

• No assistance

• Protein channels

• Energy in the form of ATP

Which molecule is too large to diffuse through the cell membrane without help?

• Potassium

• Oxygen

• Glucose

• Carbon dioxide