Osmosis Flashcards
(18 cards)
Define diffusion.
Diffusion is the random/ passive movement of particles from a high concentration to a low concentration area.
Define osmosis.
Osmosis is the passive movement of water molecules through a semipermeable membrane from a high concentration to a lower concentration of water.
Dissolved molecules end to move from areas of ______ concentration to areas of _____ concentration.
- High concentration.
2. Low concentration.
Water molecules tend to move from areas of _____ solute concentration to areas of _____ solute concentration.
- Low solute concentration.
2. High solute concentration.
Iodide solution: is the dialysis bag or the dealer hypertonic?
The beaker is hypertonic because the beaker is more concentrated in iodide then the dialysis bag is.
Which is hypotonic in relation to the starch, dialysis bag or beaker?
The beaker is hypotonic compared to the dialysis bag because the beaker has more water molecules than the solutes.
In the iodide and starch dialysis bag experiment how did you work out iodide and water moved through the membrane?
Iodide was an indicator of starch, so when the bag turned blue this mean that iodide had gone through the membrane. The bag was also a lot heavier than when it started. This meant that water had gone through as w;el, it couldn’t have been iodine because it was such a small molecule.
In the iodide and starch dialysis bag experiment was the dialysis bag selectively permeable?
It was because only certain substances could pass through. The bag only let molecules that were small enough to pass through the small openings.
Define distilled.
A technique used to purify water. Impurities and colloidal substances are removed. Other minerals can be added, such as Fluorine and Chlorine.
Define concentrated.
Lots of solute in a solvents, usually not many water particles.
Define isotonic.
Where there is the same amount of concentration f water and solutes.
Define hypotonic.
Has a lower concentration of solutes than solvent. Less concentration inside the cell then outside the cell.
Define hypertonic.
Has a higher solute concentration than the solvent. Higher concentration of solutes inside a cell then outside a cell.
Define impermeable and permeable.
Where a membrane does not allow things to pass through.
Permeable: allows liquid and gases to pass through.
What happens when there is a high water solution and a low water solution?
Water molecules move out of the cell to even out the concentration levels because of osmosis.
Homeostasis in the body.
Cells must keep the proper concentration of nutrients and water and eliminate wastes. The plasma membrane is selectively permeable, allowing some things to pass through but blocking others.
Diffusion in the body.
Occurs across membranes The cell membrane is selectively permeable. In multicellular organisms, diffusion transports oxygen, sugars, CO2, water, ions across small distances.
How does the cell wall in plants affect the process of osmosis?
Plants have a rigid cell wall on the outside of the cell membrane. This stops the cell bursting when it absorbs water. When more water is absorbed the cell becomes more rigid. Plants need this because they had no skeleton. If plants lose to much water they become less rigid and shrink. On the other hand water moves in and out of the cell membrane of animals. If water continues to move in the cell will burst and if water continues to leave cell the cell will shrink.
