EXERCISE NO. 1 Flashcards
Title of the activity 1
Demonstration of Osmosis
describes the movement of a solvent through a semipermeable membrane from a less concentrated solution to a more concentrated one
osmosis
is sometimes called “the perfect solvent,”
Water
is the best example of a semipermeable membrane
living tissue
has a number of life-preserving functions: it assists plants in receiving water, it helps in the preservation of fruit and meat, and is even used in kidney dialysis
Osmosis
can be reversed to remove salt and other impurities from water.
osmosis
The net movement of water into or out of the cell is driven by differences in _____________ between the extracellular fluid and the intracellular fluid
osmotic pressures
the effect that an extracellular fluid has on the osmotic movement of water is described by the _________ of the extracellular fluid
The ability of a solution to change the shape or tone of cells byalteringtheir internal water volume
tonicity
cellular environment occurs when an equal solute concentration exists inside and outside the cell
isotonic
Plant cells in an isotonic environment are _______, and they will wither. The equilibrium of water movement is unable to provide plant cells the internal pressure for structural support.
flaccid
In a _________________ environment, the cell has a lower concentration of solute in the environment than in the inside of the cell, making the net flow of water into the cell
hypotonic
hypotonic environment in an animal cell causes
lysis
________ environment in plant cells prevent the cell from exploding. Instead the extra water will push against the wall making it stiff or turgid ensuring plant health.
hypotonic
has a higher concentration of solutes than inside the animal or plant cell making the net flow of water out of the cell
hypertonic cell environment
The difference in concentration of solutes in the two regions (inside and out of the cell) is called a
concentration gradient
is the process in which cells lose water when they are placed in a hypertonic solution.
plasmolysis
What do you call the set-up used in the experiment?
Potato Osmometer
What plant is used for the demonstration of plasmolysis?
Hydrilla plant
is used to seal the potato after inserting the glass tubing inside the hole
Vaseline gel
What liquid is placed inside the petri dishes?
Distilled water
What are the four set-ups in the potato osmometer?
1- normal potato; salt solution inside tubing
2- normal potato; sugar solution inside tubing
3- normal potato; left empty
4- boiled potato; salt solution inside tubing
Describe the difference between set-ups 1 and 4. Give your conclusion.
1 & 2- pulls water due to osmosis
3 - potato absorbs the water
4 - no change, dead membrane
Where has the liquid in the cavities of some of the potatoes come from?
It is from the water in the petri dish which was pulled up due to osmosis.
What happened to the liquid in the dish apart from evaporation?
It was pulled up due to concentration gradient. It either went to the tube or was absorbed by the potato.
What will happen when the liquid in the cavity overflows? Explain your findings.
Some of the solute will be in the dish which will eventually distribute the concentration of in the setup and lead to equilibrium.
In what direction was the water moving (into or out of the cell) during plasmolysis? discuss.
water is moving out of the cell due to osmosis
What prevents the Hydrilla cells from complete collapsing? Discuss
The cell wall’s rigidity prevents complete collapse of Hydrilla cells during plasmolysis.
