Diffusion/osmosis

Front 1

What is the defininition of diffusion?

Back 1

is the passive movement of particles from an area of high concentration to an area of low concentration

Front 2

Where does it happen?

Back 2

in both liquids and gases because the particles are free to move about randomly

Front 3

What can be diffused?

Back 3

only very small molecules can diffuse through cell membranes. eg. glucose, amino acid, H20 and oxygen

Front 4

What affects the rate of diffusion?

Back 4

Distance - with shorter distance the substances move quicker

Concentration gradient - substances diffuse faster if there's a big difference in concentration

Surface are - the more surface for particles to move across the faster they diffuse

Front 5

Describe diffusion in the alveoli

Back 5

the blood contains lots of CO2 but little oxygen. Oxygen diffuses out of the alveolus (HC) into the blood (LC)

Carbon dioxide diffuses out of the blood (HC) into the alveolus (LC) to be breathed out.

Front 6

Describe diffusion in plants

Back 6

for photosynthesis to occur carbon dioxide must diffuse into the leaf (via the stomata) to the cells (especially the palisade cells). However, the oxygen and water vapour created by photosynthesis diffuses out of the leaf the same way

Front 7

Describe diffusion in digestion

Back 7

once big molecules like starch and proteins have broken down into glucose and amino acids. These molecules diffuse into the blood from the small intestine because their is a (HC) in the intestine. When the blood reaches the cells they diffuse.

Front 8

What is the defininition of osmosis?

Back 8

is the movement of water molecules across a semi permeable membrane from an area of high water concentration to an area of low water concentration.

Front 9

What is meant by partially permeable membrane?

Back 9

a membrane that only allows certain substances to diffuse through it.

Front 10

What is net movement?

Back 10

the solution that is strongest becomes more dilute.