hypotonic and hypertonic?

Question

so hypotonic is when there is a greater concentrarion outside the cell and hypertonic is when there is a greater concentration in the cell. we recently did a lab that show the shrinking and swelling of celery cells in the 2 solutions. i have to explain why the mass of one increased and the other decreased. i know it has to do with osmosis but i just can't seem to understand how to word it.

Answer 1

In a hypotonic solution- there is a greater concentration outside the cell... therefore- the fluid travels from a greater concentration to a lesser concentration and so it moves into the cell causing the mass to be greater and for the cell to swell..... and the opposite for hypertonic.

Answer 2

Anything soluble in water (sugars, salts) contributes to the osmolarity of the solution. When the surrounding solution has a lower concentration of solutes than the fluid of celery cells, the surrounding solution is said to be hypotonic, whereas the fluid inside the celery cells is said to be hypertonic with respect to the surrounding solution. In this situation, water enters the cells and the cells swell.

When the cells are in an isotonic solution, the amount of water that enters the cells is the same as the amount of water that leaves the cells.

When the cells are in an hypertonic solution, water leaves the cells, and the cytoplasm shrinks. This process is called plasmolysis.

Answer 3

I guess understanding the process which is the movement of WATER from a HIGH concentration to a LOW concetration.

In a "normal"situation, where the cell and solution are the same ( or isotonic = meaning same concentration) there is no net movement into or out of the cell.

In a situation where the solution is hypotonic compared to the cells ( concentration) there will be a net water movement OUT of the cell and into the hypotonic solution. THis means you will get a shrinking cell.

In a situation where the solution is hypertonic compared to the cell, then there is a net movement of water INTO the cell and swelling occurs.

Sometimes in these experiements you can chose various concentrations of solutions to get an idea of what the approx concentration of the cell is.....that will be the LEAST change in cell size ( or you can actually weigh the cells eg we used carrot pieces and weighed them before and after)....
In general there is a GREATER movment of water when there is a BIGGER difference in concentration eg solution is very hypotonic compared to the cell and you get very shrivelled cells, while a slightly hypotonic solution will give you slightly shrunken cells.

I hope this helps in some small way...