Factors that affect diffusion Flashcards
Factors that affect diffusion
steepness of concentration gradient
temperature
surface area
properties of molecules or ions
Diffusion distance / membrane thickness
How does temperature affect diffusion
Molecules and ions have more kinetic energy at higher temperatures
they move faster , resulting in a faster rate of diffusion
How does the surface area affect diffusion
The greater the surface area the greater number of molecules or ions which can cross it any moment therefore rate of diffusion is faster
How can surface area be increased
The surface area can be increased by folding e.g microvilli in intestine and cristae in mitochondria
As cells increase in size there surface area to …… ratio ….
the surface area to volume ratio decreases which slows the rate of diffusion through the cell as the distance required to travel has increased
Do large molecules or small molecules move faster and why
small molecules move faster as less kinetic energy to move
What molecules diffuse directly across the phospholipid bilayer
uncharged and non-polar molecules
Why do non polar molecules diffuse faster than polar molecules
non - polar diffuse quicker than polar as they are soluble in the non-polar bilayer
How does the steepness of gradient affect the rate of diffusion
Difference of two sides of the surface
If there are more molecule son one side than the other , at any moment randomly more molecules will move from that side to the other
a greater difference in concentration means a greater difference in the number of molecules passing in two directions leading to a faster rate of diffusion
