Biological transport mechanisms

What you'll learn

1. 1

   Imagine a crowded corridor at school during break time. People move from one end to the other, sometimes bumping into each other!

2. 2

   Picture a drop of red food colouring in a glass of water. Watch it spread out until the whole glass is pink.

3. 3

   Let's see diffusion in action! Drag the slider to add more particles on the left side and watch them spread out.

4. 4

   Oxygen moves from your lungs into your blood. How does that work? Let's break it down.

5. 5

   Diffusion moves particles from an area of…

6. 6

   But some molecules are too big or charged to slip through the cell membrane. They need a special door!

7. 7

   Which of these needs a protein channel to cross the membrane?