3.1 Diffusion Flashcards
What is diffusion
Diffusion is the net movement of particles from an area of high concentration to an area of low concentration (down the concentration gradient), due to their random movement.
What is the energy source for diffusion?
The energy for diffusion comes from the kinetic energy of the random movement of molecules and ions.
What kinds of substances move into and out of cells by diffusion?
Gases like oxygen and carbon dioxide, as well as solutes like glucose, move into and out of cells through the cell membrane by diffusion.
Why is diffusion important in living organisms?
Diffusion allows essential substances like oxygen and glucose to enter cells for processes like respiration. It also allows waste products like carbon dioxide to leave cells for excretion.
What factors affect the rate of diffusion?
The rate of diffusion is affected by:
Surface area
Temperature
Concentration gradient
Distance
How does surface area affect the rate of diffusion?
The larger the surface area, the faster the rate of diffusion, because more particles can move across a larger area.
How does temperature affect the rate of diffusion?
As temperature increases, the rate of diffusion increases because molecules move faster with more kinetic energy.
How does the concentration gradient affect the rate of diffusion?
A steeper concentration gradient (greater difference in concentration between two areas) leads to a faster rate of diffusion.
How does diffusion distance affect the rate of diffusion?
The greater the diffusion distance, the slower the rate of diffusion, as molecules must travel further.
Give an example of how diffusion happens in the body.
Oxygen diffuses from the lungs (where its concentration is high) into the blood (where its concentration is lower) so that it can be carried to cells for respiration.
