Diffusion and Osmosis Flashcards
What is diffusion?
Movement of molecules from a region of higher concentration to a region of lower concentration.
Does diffusion and osmosis require energy?
No, they are both passive.
What is active transport?
The movement of molecules across a cell membrane into a region of higher concentration with the use of energy.
Does active transport require energy?
Yes
What is:
- Permeable?
- Semi-permeable?
- Impermeable?
- Permeable - Lets everything in or out.
- Semi-permeable - Lets some in and some out.
- Impermeable - Lets nothing in or out.
What is osmosis?
The movement of water across a semi-permeable membrane from an area of high water concentration to an area of low concentration.
What’s happens if an animal cell is surrounded by a solution that is the same concentration as the cytoplasm?
The cell water will move in and out at the same rate and the cell will remain intact.
What do kidneys do in relation to osmosis?
They make sure that the plasma which surrounds our cells is at a stable concentration.
What happens if an animal cell is in a solution that is less concentrated than its cytoplasm?
The water from outside will move into the cell and may cause it to burst and die.
What’s happens if an animal cell is in a solution that is more concentrated than its cytoplasm?
Then the water may leave the animal cell and the cell will shrivel up and die.
What permeability do plant cell walls have?
They are fully permeable.
How do plants absorb water by osmosis?
If a plant cell is surrounded by a less concentrated solution, the water from outside will move into the cytoplasm and vacuole of the plant cells.
What is turgor?
When the outside water enters the plant cell, the vacuole becomes bigger and the cytoplasm swells and the cell membrane is pushed out towards the cell wall.
What is turgid?
When the cells are fully ‘swollen’ with the membrane pushing against the cell well.
What does turgor pressure do?
It gives plants their rigid shape.
