Osmosis and Water Concentration

Introduction

• Topics Covered:

  • Osmosis
  • Water concentration
  • Application to cells

• Recap of Diffusion:

  • Diffusion: Net movement of particles from higher to lower concentration.
  • Example: Oxygen or glucose molecules diffusing into a cell.

Osmosis

• Definition:
  • Special case of diffusion; specifically for water molecules.
  • Net movement of water molecules across a partially permeable membrane.
  • Movement occurs from a region of higher water concentration to lower water concentration.

Water Concentration

• Explanation:

  • Refers to the amount of water compared to other molecules (solutes) dissolved in it.
  • Solutes include molecules like sugars or salts.

• Example with Beakers:

  • Two beakers with equal water amount.
  • Left beaker with one solute particle, right beaker with three.
  • Right beaker: Higher solute concentration, lower water concentration.
  • Left beaker: Lower solute concentration, higher water concentration.
  • Key Point: Concentration determined by proportion of water to solutes, not volume of water.

Application to Cells

• Cell Environment:

  • Inside Cell: Lots of water particles, several solute particles.
  • Outside Cell: Almost pure water, few solute particles.

• Concentration Gradient:

  • Outside has higher water concentration (fewer solutes).
  • Inside has lower water concentration.

• Osmosis in Cells:

  • Water diffuses from outside (higher concentration) to inside the cell (lower concentration).
  • This diffusion process is termed osmosis.

Additional Resources

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• Video Lessons:

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  • Subject playlists available for structured learning.

End of content. Enjoy the learning resources and see you in the next session!