Substances in & out of a cell membrane

This is how molecules move in & out of a cell membrane.

The molecules move from an area of high concentration to an area of low concentration.

No energy is needed in diffusion.

This is how oxygen & glucose gets into the cell.

This is how carbon dioxide, water & urea leave the cell.

This is a plastic tube that acts as a semi-permeable membrane and allows small molecules in & out.

The small molecules can pass through if they are small enough to pass through the pores while travelling with water.

This is the movement of water from an area of high concentration to an area of low concentration through a semi-permeable membrane.

Water can move across all cell membranes.

For osmosis to happen there has to be 2 solutions of different concentrations & a partically permeable membrane to separate them.

If the concentations are the same inside & outside the cell, there is still the movement of water but no net osmosis (equilibrium).

If the cell membrane is damaged osmosis/diffusion/active transport cannot happen & the cell dies.

In a plant osmosis takes place at the root hairs.

The dissolved molecules move from an area of low concentration to an area of high concentration through a semi-permeable membrane.

Because active transport goes against the concentration gradient, energy is needed.

The molecules that are transported in active transport is minerals, salt & sugar.

The glucose moves in the blood.

In plants, the minerals move into the root hairs.