Learn: Diffusion in Biology

Welcome!Today we'll learn about diffusion, an important concept in biology. Let’s explore how substances move in and out of cells.

What is diffusion?Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. It happens in gases and liquids, where particles move freely and spread out.

How does diffusion work?Diffusion happens because particles are always moving randomly. Over time, they spread out evenly in the space available. For example, if perfume is sprayed in one corner of a room, eventually you can smell it everywhere as it diffuses through the air.

Why is diffusion important in biology?Diffusion is vital because it allows substances to move in and out of cells. For example, oxygen diffuses into cells for respiration, and carbon dioxide diffuses out as a waste product.

Factors affecting diffusionSeveral factors can influence the rate of diffusion, such as:Concentration gradient: Particles diffuse faster when there’s a large difference in concentration.Temperature: Higher temperatures increase particle movement, speeding up diffusion.Surface area: Bigger surface areas allow more particles to pass through.

Diffusion in the human bodyIn humans, diffusion happens in the lungs. Oxygen diffuses from the air in the alveoli into the blood, while carbon dioxide diffuses out from the blood into the alveoli to be exhaled.

Review Time!Great work! You've learned about diffusion, its process, importance, and factors affecting it. Now let’s test your understanding with some final questions.