YV4-cells-diffusion

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Cells & Osmosis

Diffusion

Describe what happens in the video

Diffusion

• Molecules move from a high to a low concentration
• The movement of molecules is random
• This is a form of passive transport, because the energy comes from the molecules themselves

How does heat affect diffusion?

What is the effect of distance on diffusion?

The shorter the distance, the faster the molecules will have equal concentrations throughout the space

What is the effect of surface area on diffusion?

The bigger the surface area, the faster the molecules will be evenly distributed over the available area

What is the effect of concentration gradient on diffusion?

The bigger the difference in concentration, the faster diffusion will happen

Misconceptions with diffusion

• Molecules want the concentration to be equal/ try to make the concentrations equal. Molecules have no mind to think with, they move randomly
• Molecules stop moving after the concentrations are equal. Molecules never stop moving, but when concentrations are equal there are equal amounts of molecules moving in every direction.

Questions

Which process is responsible for gas exchange in the lungs?

What have multi-celled organisms developed in order to provide an increased surface area for gas exchange?

Why do large multicellular organisms need transport systems while simple unicellular organisms do not?

Learning Objective

- You can explain the process of diffusion.