Diffusion Flashcards
What is the definition of diffusion?
Diffusion is the movement of particles from a region of high to low concentration.
Where does diffusion take place?
Diffusion takes place in solutions and gases
What is the simplest type of diffusion?
The simplest type of diffusion is gases through gases
What happens with a bigger concentration gradient?
The rate of diffusion increases as the concentration gradient increases
Name one factor that increases the rate of diffusion and explain why.
Temperature:
The particles gain more kinetic energy meaning there movement is faster so there is more frequent collisions and therefore a quicker rate of diffusion.
Diffusion in cell membranes:
What is the function of a cell membrane?
They hold the cell together and allows things to enter and leave the cell.
How do substances enter and leave substances?
Substances can enter and exit the cell by diffusion but they have to be DISSOLVED.
What type of molecules are involved in diffusion?
Small molecules ONLY
Name four examples of small molecules.
- Oxygen
- Glucose
- Amino acids
- Water
Name two molecules that cannot diffuse-
Why?
- Starch
- Proteins
As they are too big to fit through the membrane
Can particles diffuse through a cell membrane?
Yes
If there is a higher concentration of particles on one side of the membrane what is there?
A NET (overall) movement from that side.
Name another factor that increases the rate of diffusion and explain why.
A larger membrane surface area
Because more particles can pass through at once.
