3.6 Osmosis Flashcards
Osmosis only involves water molecules, it is a…
Passive process, because it relies only on the kinetic energy of the water molecules
Water potential measures the…
Pressure water molecules exert in a solution, and their ability to move freely. The more water there is, the higher the water potential and the more freely the molecules can move
Water molecules move by osmosis from a region of…
Higher (less negative) water potential to a region of lower (more negative) water potential
Osmosis is the movement of water molecules from a region of…
Higher water potential to a region of lower water potential across a partially permeable membrane
Difference in concentration is called a…
Water potential gradient
The membrane is partially permeable, so only…
The water molecules can pass through it
Eventually the water potential on both sides of the membrane will be the same, at this point…
Equilibrium is reached and there is no net movement of water
3 types of osmosis solutions in animal cells:
Hypotonic
Hypertonic
Isotonic
If the solution has a higher water potential than the solution inside the cell it is a…
Hypotonic solution
If the solution has a lower water potential than the solution inside the cells it is a…
Hypertonic solution
If the solution has he same water potential as the solution inside he cell it is a…
Isotonic solution
If the animal cell (red blood cell) is placed in pure water, it will take in water by osmosis because the water has a higher water potential than the solution inside the RBC, this causes it to…
Swell up because the cell-surface membranes are very thin and not able to stretch very much
If the cell takes in more than a small amount of water it will burst releasing its cell contents
If a RBC is placed in a hypertonic solution (concentrated salt solution), it will lose water because…
The salt solution has a lower water potential than the red blood cell - RBC will shrink and shrivel up
Normally cells inside the body do not swell up or shrink as a result of osmosis because the water potential of the fluids surrounding body cell (blood plasma) is carefully controlled…
Isotonic
Plant cells have a strong cellulose cell wall surrounding the membrane this means when a plant cell is placed in pure water it…
Swells up but it cannot bra because the cell wall acts like a ‘cage’
The cell pushes against the cell wall - turgid
