Movement of substances in/out of cells Flashcards
What is the definition of diffusion?
Diffusion is the net movement of particles from an area of high concentration to an area of low concentration, moving down the concentration gradient. It is passive as it doesn’t require energy.
What is the definition of osmosis?
Osmosis is the net movement of water
particles from an area of high water potential to an area of low water potential across a partially-permeable membrane, moving down the concentration gradient. It is passive as it doesn’t require energy.
Where can diffusion happen?
In fluids
Where can osmosis happen? (Example)
Anywhere in the movement of water, plants take water and nutrients from roots
Name the 4 factors that can affect the rate of movement of the substances into/out of cells
- Surface area to volume ratio
- Distance
- Temperature
- Concentration gradient
How does surface area to volume ratio affect the rate of movement of substances into/out of cells?
As the surface area of the membrane increases, the rate of diffusion also increases, as there is more space for molecules to diffuse across the membrane.
How does distance affect the rate of movement of substances into/out of cells?
The shorter the distance the substances have to move, the faster the rate of diffusion as they have less distance to travel.
How does temperature affect the rate of movement of substances into/out of cells?
The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly.
How does the concentration gradient affect the rate of movement of substances into/out of cells?
The greater the difference in concentration, the more rapid the diffusion. The closer the distribution of the material gets to equilibrium, the slower the rate of diffusion becomes.
What is hypertonic?
-Hypertonic (water leaving the cell)
What is isotonic?
-Isotonic (equilibrium of water)
What is hypotonic?
-Hypotonic (water entering the cell )
