diffusion and facilitated diffusion Flashcards
1
Q
where does diffusion happen?
A
across the cell surface membrane
2
Q
what is the definition of diffusion?
A
the net movement of particles from a region of high concentration to low concentration
3
Q
do molecules move up or down the concentration gradient in diffusion?
A
down
4
Q
what are the 4 main factors effecting the rate of diffusion?
A
- temperature
- steepness of concentration gradient
- surface area
- properties of the molecule
5
Q
why does temperature increase diffusion?
A
there is more kinetic energy
6
Q
why does a higher surface area mean more diffusion?
A
more molecules can cross at any given time
7
Q
why do smaller molecules diffuse quicker?
A
large molecules need more energy
8
Q
why do non-polar molecules diffuse quicker?
A
they are soluble in the phospholipid bilayer
