How do cells maintain water balance through osmosis?

egg osmosis lab

solution egg mass (g) initial egg mass (g) after 24 hrs/ student observations
vinegar 45 - 85 shell gone; egg seemed swollen and larger
10% salt water 85 - 85 no change in egg appearance or size
kayro syrup 85 - 31 egg was wrinkled and shriveled; much smaller
distilled water 85 - 105 egg was larger in size; swollen and tight

solution concentration can be described in terms of tonicity. solutions are hypertonic, isotonic, or hypotonic to cells. a hypotonic solution is one in which the concentration of solutes is greater inside the cell than outside of it. water will enter the cell via osmosis, to the outside environment. water moves into the cell and the cell swells. if enough water enters, the cell can burst. an isotonic solution is a balanced solution. that is, the solution concentration is balanced with the solution inside the cell. finally, when a cell is surrounded by a hypotonic solution, concentration of solute is greater outside the cell..this is one reason why organisms that live in fresh water cannot survive in salt water, the ocean. water will leave the organism’s cells and eventually the cells will undergo plasmolysis and the organisms will die. m

in this lab activity, students performed an experiment using eggs to observe the effect of osmosis on cells. the egg represented a typical cell. before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells. what they had in hand, then, was actually a raw, shell-less egg.

student procedure:
day 1 – students found the mass in grams of their shelled eggs, recoding the mass in the data table. the eggs were placed in a beaker and covered with 200 ml vinegar to remove the shells. vinegar, a mild acid, reacts with the calcium carbonate in the shell and the shell should disappear.

day 2 – the eggs were removed from the vinegar. visual observations were recorded. the shell-less eggs were wiped dry, massed, and the mass was recorded in the data table. the eggs were placed in a clean beaker and covered with a 10% salt-water solution.

day 3 – the eggs were removed from the salt water and visual observations were made and recorded. the eggs were wiped dry , massed, and the mass was recorded. the eggs were placed in a clean beaker and covered with sugar (kayro) syrup.

day 4 – the eggs were removed from the syrup and visual observations were made and recorded. the eggs were carefully wiped with a damp cloth, massed, and the mass was recorded.

how do cells maintain water balance through osmosis?

a) if a salt water fish is placed in a fresh water aquarium, water will leave the fish's cells.
b)in the experiment, the only isotonic solution was the 10% salt water solution
c)the egg swelled in distilled water because it is hypotonic to the egg's interior.
d)the concentration of solute is greater inside the egg than it is in the kayro syrup.
e)he egg swells when placed in a hypertonic solution.