diffusion Flashcards
1
Q
what is diffusion
A
the movement of small and non polar molecules from a high to low concentration - passive process
2
Q
factors affecting diffusion
A
- concentration gradient
- membrane thickness
- temperature
- surface area
3
Q
what is facilitated difussion
A
this is a specialised diffusion which must be carried out for large and polar molecules
4
Q
how do large molecules diffuse
A
large molecules attach to carrier proteins (integral) and so they change shape allowing the molecule through to the other side
5
Q
how do polar molecules diffuse through
A
they fit through channel proteins which are a tunnel shape
6
Q
factors affecting facilitated diffusion
A
- concentration gradient
- number of channel and carrier proteins in the membrane
