2.5.3 diffusion Flashcards
definition of diffusion?
the passive, net movement of particles from a region of higher concentration to a region of lower concentration until equilibrium is reached
why does diffusion happen?
because the particles in a gas or liquid have kinetic energy that caused random movement which eventually evens out an unequal distribution of particles so there’s equal movement in both directions
how does temperature affect the rate of diffusion?
the higher the temperature the higher the rate of diffusion as the particles have more kinetic energy and move at higher speeds
how does concentration difference/gradient affect the rate of diffusion?
the greater the difference in concentration between 2 regions the faster the rate of diffusion because there’s a larger overall movement of particles
how does surface area and size affect the rate of diffusion?
the larger the area of an exchange surface the more diffusion can take place
the smaller the molecules the faster the rate of diffusion
how does distance affect the rate of diffusion?
the longer the diffusion distance the slower the rate of diffusion because more collisions occur between particles
what’s facilitated diffusion?
diffusion across a membrane via protein channels
why do we need facilitated diffusion?
to allow polar molecules/ions to diffuse across the phospholipid bi-layer
what’s another factor that affects facilitated diffusion?
the number of channel proteins present; the more there are the higher the overall rate of diffusion
