Osmosis Lab Report

Osmosis is defined as the net movement of water across a semipermeable membrane. Osmosis can cause cells to swell and sometimes burst. We can see this property in the lab we did in class. When we put gummy bears in the water they grew up to 500% of their original size. This happened because the water was entering the cells, causing them to swell and increasing the size and mass of the gummy bears. When cells grow due to osmosis it causes two different things to happen, based on the cell. If it is an animal cell then cytolysis will happen, which is the bursting of the cell. This can be seen with the gummy bears because they got so big that they almost burst and were too fragile to pick up. The second thing that happens is seen in plant cells. When a plant cell aborbs lots of

We saw this with the cherries and raisins, which expanded but were not as fragile and easier to handle. In osmosis, water moves from high to low concentration. We see this property in the second part of the lab. When we looked at the elodea cell in distilled water under a microscope, we were able to see the cell wall making the rectangular shape and the cell membrane along with other organelles placed around the outside of the cell. When we put the cell under salt water, the cell membrane contracted, bringing all the organelles into the middle of the cell like a drawstring bag. What happened is that water left the cell because it moved towards the salt water outside of the cell. This condition is called playsmolysis and happens in both plant and animal cells. Water is constantly moving and trying to maintain equilibrium which is a balanced concentration of solutions on either side of the cell. Osmosis causes water cells and other molecules to move from high concentration to low concentrations to make everything equal. The last part of the lab further proves this