Osmosis and Its Effects on Cells

Key Concepts

• Osmosis Definition:
  • The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Basic Ideas

• Dilute vs Concentrated Solutions:
  • Dilute Solution: Contains a high concentration of water.
  • Concentrated Solution: Contains a low concentration of water.
• Partially Permeable Membrane:
  • Allows some molecules to pass through, such as water molecules, but not others like sugar molecules.

Process of Osmosis

• Water diffuses from an area of higher concentration (dilute solution) to one of lower concentration (concentrated solution).
• Example: Water moves from the left side (higher concentration) to the right side (lower concentration) through a membrane.

Effects of Osmosis on Cells

Animal Cells

• In Water:
  • Water moves into the cell by osmosis, causing it to expand.
  • Potential cell burst if excessive water enters.
• In Concentrated Solution:
  • Water moves out of the cell by osmosis, causing the cell to shrink.

Plant Cells

• In Water:
  • Water moves into the cell by osmosis, causing the cell to expand.
  • The cell wall prevents bursting, and the cell becomes swollen or turgid.
• In Concentrated Solution:
  • Water moves out of the cell, causing it to shrink.
  • The cell becomes flaccid.

Study Tips

• Practice questions on osmosis are available in the revision workbook linked in the video.