Osmosis Flashcards
what is osmosis?
the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower concentration
what is a partially permeable membrane?
it allows some molecules to pass through but not all
where does osmosis take place?
only in water
what would happen if you placed an animal cell in a concentrated solution?
•water would move from inside the cell (an area of high water concentration) to outside the cell (an area of low water concentration) across a partially permeable membrane by osmosis
•this would cause the cell to shrink
does a concentrated solution contain more water or solute?
more solute therefore concentrated solutions contain a low concentration of water
does a diluted solution contain more solute or water?
it contains more water therefore dilute solutions contain a high concentration of water
what would happen if you placed a plant cell in water?
•water would move from outside the cell (an area of high water concentration) to inside the cell (an area of low water concentration) by osmosis through a partially permeable membrane
•this would cause the cell to expand however the cell wall prevents the cell from bursting so it becomes turgid instead
what does turgid mean?
swollen
what happens in you place a plant cell into a concentrated solution?
•water would move from inside of the cell (an area of high water concentration) to outside the cell (an area of low water concentration) across a partially permeable membrane by osmosis
•this would cause the cell to shrink and become flaccid
what does flaccid mean?
soft and hanging losely
what is potato experiment to show the affect of osmosis?
•cut up a potato into identical cylinders and get some beakers with different sugar solutions in them. One should be pure water and another should be a very concentrated solution
•measure the mass of the potato cylinders and leave one in each beaker for around 20mins
•after 20mins take the potato cylinders out of each beaker, dry them with a paper towel to remove excess and measure their masses again
what would the dependent variable be in the potatoes experiment?
the potato cylinder mass
what would the independent variable be for the potato experiment?
the concentration of the solution
what are some control variables for the potato experiment?
the volume of solution, temperature, type of solute used e.g. sugar or salt
what are some errors that could occur during the potato experiment?
•if the potato cylinders were not fully dried then the excess water could give them a higher mass
•if water evaporated from the beakers the concentration of the concentrated solutions wouldn’t change
