4.3 - Osmosis Flashcards
The definition of water potential The process of osmosis Factors affecting the rate of osmosis
What is a solution?
Mixture of solute dissolved in a solvent
What is water potential (Ψ)?
Pressure exerted by water molecules on a membrane
What units is water potential measured in?
kiloPascals (kPa)
What does high water potential mean?
High water concentration
What does low water potential mean?
Low water concentration
What is the water potential of pure water?
0 kPa
What is osmosis?
Diffusion of water across a partially permeable membrane
What type of molecules can diffuse through the cell membrane?
Water molecules
What happens during osmosis?
Water moves down a water potential gradient to equilibrium
What happens to animal cells in a hypotonic solution?
Water moves in
What happens to animal cells in an isotonic solution?
No net water movement
What happens to animal cells in a hypertonic solution?
Water moves out
What happens to plant cells in a hypotonic solution?
Water moves in
What happens to plant cells in an isotonic solution?
No net water movement
What happens to plant cells in a hypertonic solution?
Water moves out
What factors affect the rate of osmosis?
Temperature
How does temperature affect osmosis?
Higher temperature
How does water potential gradient affect osmosis?
Steeper gradient
How does membrane thickness affect osmosis?
Thinner membrane
How does surface area affect osmosis?
Larger surface area
