Learn: Diffusion and Osmosis

Welcome!Today, we'll learn about diffusion and osmosis, two important processes in biology. These help substances like gases and water move in and out of cells, which is vital for life!

What is Diffusion?Diffusion is the movement of particles from an area of high concentration to an area of low concentration. It happens passively, meaning it does not require energy. For example, oxygen diffuses into the blood from the lungs because there is more oxygen in the air than in the blood.

What is Osmosis?Osmosis is the movement of water molecules across a selectively permeable membrane, from an area of high water concentration to an area of low water concentration. This process is crucial for maintaining the balance of fluids inside and outside cells.

What is Active Transport?Active transport is the movement of substances against their concentration gradient, from a lower concentration to a higher concentration. This requires energy, usually provided by ATP (adenosine triphosphate). For example, root hair cells use active transport to absorb minerals from the soil.

Comparison of Diffusion, Osmosis, and Active TransportThese processes are different ways substances move in and out of cells:Diffusion: Movement of particles from high to low concentration without energy.Osmosis: Movement of water across a membrane from high to low water concentration.Active transport: Movement of substances against the concentration gradient, requiring energy.

Review Time!Great work! You've learned about diffusion, osmosis, and active transport. Let's test your understanding with a few questions.