Diffusion Flashcards
1
Q
what is diffusion?
A
the random movement of particles from an area of high concentration to an area of lower concentration
2
Q
what are the four main factors that affect the rate of diffusion?
A
- temperature
- concentration gradient
- distance
- surface area: volume
3
Q
how does temperature affect diffusion?
A
- at higher temperatures, molecules have more kinetic energy and so move faster
- therefore diffusion occurs faster
4
Q
how does concentration gradient affect diffusion?
A
- if there is a large difference in the concentration between two areas, molecules will diffuse from the higher to the lower concentration quicker than if there is only a small difference
5
Q
how does distance affect diffusion?
A
- diffusion takes longer if the molecules have to travel further (molecules don’t travel in a straight line)
- therefore cells are small (smaller volume reduces disance)
6
Q
how does surface area: volume affect diffusion?
A
- a larger surface area speeds up the rate of diffusion as there are more opportunities for the molecules to move, which is why surface such as alveoli in lungs are so large
7
Q
how does surface area to volume ratio affect diffusion?
A
- (this is more significant as the two counteract each other)
- an efficient exchange surface area which is very large compared to the distance the molecules must travel (SA:V is increased when structures are small)
