Diffusion Flashcards
What is the definition of diffusion?
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
Why does diffusion not happen in solids?
Because the particles in a solid are not free to move about randomly
What is the simplest type of diffusion?
When different gases diffuse through each other
What is an example of diffusion?
When perfume diffuses through the air in a room
How do dissolved substances move in and out of cells?
Diffusion
When does diffusion occur more rapidly?
When there is a larger difference in concentration, when the particles have more energy (higher temperature) and when the surface area is bigger
What is the difference in concentration between two areas called?
The concentration gradient
In cells, what do things diffuse through?
The cell membrane
Give an example of 4 things which can diffuse through a cell membrane
oxygen, water, amino acids and glucose
What cannot fit through a cell membrane?
Big molecules like starch and proteins
How do particles move about in a cell
Randomly
Do particles move both ways or only one way through a cell membrane?
Both ways
What will happen when there are more particles on one side of a cell membrane?
There is a net (overall) movement from the side with more particles
What are some examples of types of diffusion that happens in cells?
diffusion of oxygen into body cells from the bloodstream, diffusion of CO2 into actively photosynthesising plant cells, diffusion of simple sugars and amino acids from the gut through cell membranes
