Osmosis in Plants (Cambridge International IGCSE Science)

Osmosis in Plants: Extended

Spec point — Explain the effects on plant cells of immersing them in solutions of different concentrations by using the terms: turgid, turgor pressure, plasmolysis, flaccid

Plant cells in solutions of different concentrations

• When plant cells are placed in a solution that has a higher water potential(dilute solution) than inside the cells (e.g. distilled water) then water moves into the plant cells via osmosis
• These water molecules push the cell membrane against the cell wall, increasing the turgor pressure in the cells which makes them turgid

A turgid plant cell

• When plant cells are placed in a concentrated solution (with a lower water potential than inside the cells) water molecules will move out of the plant cells by osmosis, making them flaccid

  • If plant cells become flaccid it can negatively affect the plant's ability to support itself

• If looked at underneath the microscope, the plant cells might be plasmolysed, meaning the cell membrane has pulled away from the cell wall

A plasmolysed plant cell