Diffusion Flashcards
What is the definition of diffusion?
Diffusion is the spreading out of particles from an area of high concentration to an area of low concentration.
Where does diffusion happen?
In solutions and gases because the particles are free to move about. The bigger the difference in concentration, the faster the diffusion rate.
What is diffusion in cells?
Dissolved substances moving in and out of the cell through the membrane.
What can diffuse through the cell membrane?
Only small molecules such as oxygen, amino acids, water and glucose. Larger molecules such as fats, proteins and starch can’t get through.
The cell membrane is…?
Semi-permeable.
Which way do they cross the cell membrane?
Both ways, but there is a net movement from high to low concentration (the concentration gradient).
