Osmotic Pressure

What is osmosis? (1)

Movement of water across a semi-permeable surface

What is a Hypertonic Solution and how does that affect bacterial cells? (3)

• Lots of solute (salt/sugar) outside the cell

• Water will move to outside of cell causing the cell to dry up

• The cell dies via Plasmolysis

What is a Hypotonic Solution? (3)

• Lots of solute inside the cell

• Too much water moves inside the cell causing it to bursts

• Cell dies Via Osmotic lysis

What is an isotonic solution? (1)

The solute inside cell = solute outside cell

What are some foods/food products that can be preserved from osmotic pressure? (2)

• Salted fish

• Honey (high sugar content)

Some bacteria have adapted to high salt concentrations, requiring up to how much NaCl? what are these bacteria called? (1)

• 30%

• extreme halophiles

Where can extreme Halophiles be found? (1)

The dead sea (around 30% salt concentration)

What is interesting about blood being a 0.9% salt concentration in regards to pathogens? (1)

• Most pathogens prefer a 1% concentration (does not inhibit growth of most micro organisms)