What is Osmosis?

it is the movement of the solvent through a semi-permeable membrane to a higher solvent concentration, in order to equalize the amount of solvent concentration on both sides. Basically, they transport substances.

Hypotonic, Hypertonic and Isotonic

Hypotonic - is where there is solute is too so the water moves into the cell via osmosis

Hypertonic - is when there is very high solute so the water moves out of the cell via osmosis

Isotonic - is when the solute is stable

Questions

What would occur if instead, a freshwater fish is placed in salt water?

The fish is hypotonic as it doesn't have enough solvents, thus why they live in fresh water; when put in saltwater - which is hypertonic - the fish is most likely to shrivel up because there is too much solvent that the fish's body can't handle

Finish the statement:

The fluid movement to the brain after a traumatic brain injury can result in a dangerous brain swelling.

One treatment that can be used in some of these cases is adding a ____hypertonic____ saline.

The hypertonic saline attracts the excess fluid, which is hypotonic, reducing the damage - much like the example of the freshwater fish in saltwater.

Your sister decides to dump gummy bears in ice water for about 30 minutes before you get home. They are greatly enlarged by the time you get home. Why?

The water travelled into the gummy bear because the gummy bears were hypertonic, compared to the water. There was a lot more solvent in the gummy bear which took in a lot of water as the water is hypotonic and the absorption happened through osmosis.

When you do a transporting substance graph:

It is a line graph and there is a line in the middle. If there is no 'net movement', it means that it isotonic. Provide the correlation, facts and figures. The line in the middle is the concentration and the line on the side is the percentage/change in mass.

the percentage change in mass is always used to show how big the change was, relative to the existing mass. Eg: if there was a mass of 1g and a difference of 1g, it would make a lot of difference but if it was 1kg and changes by 1g - there is is not much of a difference.

how to calculate Percentage Change in Mass:

Change in mass / initial mass x 100 = PCM

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	Created by Rhea Ramesh about 7 years ago

Some revision notes on Osmosis for a Biology exam!