Movement into and out of cells Flashcards
What is diffusion?
The net movement of particles from a region of their higher concentration to a region of their lower
concentration as a result of their random movement.
Where does the energy for diffusion come from?
The kinetic energy of random movement of molecules and ions
What is a way that substances move into and out of cells?
Diffusion through the cell membrane
Why is diffusion important in living organisms?
It allows them to gain the useful substances they require to obtain energy and grow, and lets them get rid of waste products.
What is the concentration gradient?
The difference in the concentration of a chemical across a membrane.
How does surface area affect diffusion?
The greater the surface area, the faster the rate of diffusion.
How does temperature affect diffusion?
The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly.
How does concentration gradient affect diffusion?
The greater the difference in concentration, the quicker the rate of diffusion.
How does distance affect diffusion?
The greater the distance that a substance must travel, the slower the rate of diffusion.
What is osmosis?
Top level GCSE extended
Osmosis is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane.
What do you call a plant cell filled with water?
Turgid
What do you call a plant cell that loses water?
Flaccid
What is plasmolysis?
The cytoplasm shrinks and pulls away from the cell wall.
What is turgor pressure?
- The cell wall stops the cell from exploding.
- When the water pressure inside the cytoplasm is equivalent to the water pressure outside, it stops.
- This is called TURGOR PRESSURE and the cell has become turgid.
- The pressure created by the cell wall stops too much water entering and prevents cell lysis.
Consider a plant cell in dilute solution. What’s gonna happen?
Water will enter through the cell membrane and the cell eventually becomes TURGID.
