Diffusion Flashcards

All 6 cards in this deck

What is diffusion?

The net movement of particles from an area of higher concentration to an area of lower concentration, down a concentration gradient. It is a passive process.

What is meant by moving 'down a concentration gradient'?

e.g. oxygen moving from blood into a body cell

Moving from where the substance is more concentrated to where it is less concentrated.

e.g. oxygen moves from blood (high oxygen) into the cell (low oxygen).

Name three factors that affect the rate of diffusion.

The concentration gradient (difference in concentration), the temperature, and the surface area of the membrane.

True or false? Diffusion is the movement of particles in one direction only.

False. Particles move randomly in all directions; diffusion is the net movement down the concentration gradient.

True or false? Cooling a cell increases the rate of diffusion into it.

False. At lower temperatures particles have less energy and move more slowly, so diffusion is slower.

Name two substances that move into or out of animal cells by diffusion.

Oxygen (into the cell) and carbon dioxide (out of the cell). Urea is also accepted.