Zusammenfassung der Ressource
Diffusion
- The random movement of small
particles from an area of high
concentration to an area of low
concentration
- Pass between small gaps between
phospholipid molecules or dissolves in lipid
layer
- Passive process, no ATP required
- No membrane proteins
needed
- Examples
- O2
- CO2
- Vitamin A,D,E
- Factors affecting rate
- Concentration Gradient
- Higher the concentration
gradient the more likely a
molecule will collide with
the membrane and cross it
- Temperature
- As temp increases molecules gain kinetic
energy so moves faster, so collides with
membrane more frequently
- Size of molecule
- The larger the molecule the harder
it is to fit between phospholipids
- Lipid solubility
- The more lipid soluble a molecule is,
the easier it is to dissolve and cross
bilayer
- Distance
- The longer the diffusion path, the
more distance the molecule needs
to travel so the longer it takes
- Surface Area
- As S.A increases the more
spaces for diffusion to
happen