movement of substances

allows all substances to pass through (cell wall)

permeable membrane

allows some substances to pass through and excludes others (cell membrane)

Semi Permeable

Water and Oxygen can enter freely, Carbon Dioxide can exit freely and Salts, Sugars and Proteins cannot enter or exit freely.

Advantage of cell membrane being semi permeable

nucleus, mitochondria, chloroplasts

Three locations INSIDE a cell that are semi permeable

Water will enter by osmosis, Cell swells up and may burst and die

Osmosis in animal cell(fresh water)

Water leaves by osmosis, cell shrivels up and may die

Animal Osmosis (high solute solution)

Water enters by osmosis cell wall prevents cell bursting Very turgid

Osmosis in plant cell (distilled)

Cell wall and Vacuole

Two features of plant cells allows cell to be turgid for a long time

Take in water by osmosis to offset water loss

HOW do plants remain turgid for long amounts of time

Absorbs water through root hairs by osmosis

How do plants take in water

Water leaves by osmosis, Cytoplasm and Vacuole shrink. Membrane moves away from cell wall and he cell becomes plasmolysed

Plant in high solute solution

Loss of water from the vacuole and cytoplasm movement of the cell membrane away from cell wall

whats plasmolysis

Turgid cells are Strong and upright. Plasmolysed cells lack support, wilts and dies

Turgidity affect on plants

Animal cells dont have a cell wall causing water entering by osmosis to burst it.

why cant animal cells be turgid

Why dont animal cells need to be turgid

They have a skeleton

Fish and Meat may be soaked in salty solutions and any micro organisms will lose water by osmosis and die.

How can osmosis be used to preserve food

High sugar concentration in jams and marmalades, any micro organisms will die by losing water by osmosis.

osmosis preserving food (b)

Movement of substances from a low region of concentration to a high region of concentration.

Whats active transport

Minerals are absorbed by root hairs by active transport from the soil (magnesium)

example of active transport in plant

Some glucose, amino acids and salts are reabsorbed by active transport from the nephron in the kidney into the bloodstream

Example of active transport in an animal

Half fill one piece of visking tubing with a concentrated sucrose solution and the other with distilled water. Seal each and record their weight, then leave them in water for 30 mins take them out dry them off and record mass again

Experiment demonstrating osmosis

Its used as a control

Why is the visking tubing with distilled water used.

comparison against the actual experiment proving the actual experiment is valid.

whats a control

Visking tubing with a high solute solution will be heavier because water left by osmosis.

results of the expirment