C3.1 Diffusion Lecture Notes

Practice vocabulary flashcards covering the definition, mechanism, influencing factors, and biological examples of diffusion.

Diffusion

The net movement of particles from a region of higher concentration to a region of lower concentration until the particles are evenly distributed.

Net movement

The overall movement where particles still move randomly in all directions, but more particles move out of the high concentration area than into it.

Concentration

The number of particles in a given volume.

Concentration gradient

The difference in concentration between two areas.

Equilibrium

The condition reached when particles are evenly distributed throughout and there is no net movement.

Kinetic energy (in diffusion)

The energy particles gain when temperature increases, causing them to move faster and increase the rate of diffusion.

Surface area (effect on diffusion)

A factor that, when increased, provides more area for particles to diffuse through, resulting in faster diffusion.

Diffusion distance

The thickness or distance particles must travel; increasing it causes slower diffusion.

Particle size and weight (effect on diffusion)

A factor where smaller and lighter particles move faster, leading to a faster rate of diffusion.

Alveoli

Structures in the lungs with a short diffusion distance and large surface area where oxygen diffuses into the blood and carbon dioxide diffuses into the lungs.

Root hair cells

Plant cells into which mineral ions diffuse from a higher concentration in the soil to a lower concentration inside the plant.

Stomata

Openings in plant leaves through which gases diffuse in and out.