Learn: Diffusion in Biology

Welcome!Today we'll learn about diffusion, a key process in biology. It's part of the OCR GCSE Combined Science J250 curriculum. Let's explore step by step!

What is Diffusion?Diffusion is the movement of particles from an area of high concentration to an area of low concentration. It happens in gases and liquids, where particles move randomly. This process is essential for many biological systems, like the movement of oxygen into cells.

Why does Diffusion matter?Diffusion is crucial for cells to receive nutrients and oxygen while removing waste products like carbon dioxide. Without diffusion, cells wouldn't function properly, and life wouldn't be possible.

Factors affecting DiffusionSeveral factors influence diffusion:Concentration Gradient: The bigger the difference in concentration, the faster diffusion happens.Temperature: Higher temperatures increase the speed of particle movement, speeding up diffusion.Surface Area: A larger surface area allows more particles to move at once.Distance: Shorter distances make diffusion faster.

Examples of DiffusionDiffusion occurs all around us:Oxygen moving from the lungs into the blood.Carbon dioxide moving from the blood into the lungs to be exhaled.Perfume spreading through a room.Food colouring dispersing in water.

Diffusion in CellsIn biology, diffusion happens across cell membranes. For example, oxygen and glucose diffuse into cells for respiration. Carbon dioxide diffuses out as a waste product. Cell membranes are partially permeable, meaning only certain substances can pass through.

Review Time!Great work! You've learned about diffusion, its importance, factors affecting it, and examples in biology. Let's test your understanding with a few questions.