2.4 Movement of substances in and out of cells Flashcards
Diffusion
the net movement of substances from an area of high water potential to low water potential
Osmosis
the net movement of water from an area of high water potential to low water potential through a partially permeable membrane
Active transport
the movement of substances from an area of low to high concentration, against a concentration gradient, using the energy from ATP
Concentration Gradient
the difference in concentration between two areas
Surface area to volume ratio
the size of the object compared with the area that is in contact with the environment
Isotonic solution
the solution outside the cell has the same water potential as inside the
cell - no net movement
Hypotonic solution
the solution outside the cell has a higher water potential then inside
the cell - net movement of free water molecules into the cell
Hypertonic solution
the solution outside the cell has a lower water potential then inside
the cell - net movement of free water molecules out of the cell
When placed in a Hypotonic solution, state what would happen and the name given to both a plant and an animal cell
plant: turgid (normal) (cell wall prevents bursting)
animal: lysed (bursts because no cell wall to provide strength and maintain structure)
When placed in a Hypertonic solution, state what would happen and the name given to both a plant and an animal cell
plant: plasmolysed (wilt, not enough water to fill their cells therefore cytoplasm shrinks from the cell wall)
animal: shrivelled
Potato chips in a sucrose solution experiment method:
Potato chips can be placed in sucrose or salt
solutions of different concentrations.
1. put potato chips of the same size in sucrose or salt solutions of different concentrations
2. Osmosis will occur until the water potential
of the tissue and solution are the same; this
causes a mass change
–> If the solution has a higher water
concentration, water will move into
the potato chip and the mass will
increase
–> If the solution has a lower water
concentration, water will move out of
the potato chip and the mass will
decrease
Examples of biological molecules
Glucose is absorbed by active transport in the small intestine
plants use active transport in their root hair cells to absorb mineral ions.