7. Reflections
After this experiment, we have learnt alot more about osmosis and its effects on objects submerged in solutions with higher water potential. We found it enjoyable to carry out this experiment even though it could sometimes get messy, example, when the egg submerged in bleach bursts. We would like to have more experiments like this as it is a fun way to learn more about biology topics! =D
6. Explanation
Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane. A selectively permiable membrane is one that allows unrestricted passage of water, but not solute molecules or ions.
Different concentrations of solute molecules leads to different concentrations of free water molecules on either side of the membrane. On the side of the membrane with higher free water concentration (i.e. a lower concentration of solute), more water molecules will strike the pores in the membrane in a give interval of time. More strikes equates to more molecules passing through the pores, which in turn results in net diffusion of water from the compartment with high concentration of free water to that with low concentration of free water.
The key to remember about osmosis is that water flows from the solution with the lower solute concentration into the solution with higher solute concentration. This means that water flows in response to differences in molarity across a membrane. The size of the solute particles does not influence osmosis. Equilibrium is reached once sufficient water has moved to equalize the solute concentration on both sides of the membrane, and at that point, net flow of water ceases. Thus, the eggs placed in green tea and distilled water became longer,bigger and turgid as the water molecules moved from the green tea and distilled water into the eggs through osmosis.
Whereas the egg placed in bleach may have burst due to too much water molecules entering the egg, causing it to expand too much and burst or too much water molecules exiting from the egg causing the cells of the egg to crenate and thus, causing the egg to burst.
5. Properties of egg after being submerged in the different solutions.
Description (felicity's version of the story)
This was when the foolish sasha decided to play a fool by asking felicity to put the egg that had been submerged in distilled water overnight into a beaker of bleach that contained a burst egg. Then, it spilled.
Then, felicity's poor bar counter was like disfigured. Yeah, thanks to sasha who really cannot estimate properly. Lets not go for a drink with her anymore or she will spill it all over you.!!
4. Properties of eggs before being submerged in different solutions.
1. What is inside an egg?
2. Why deshell the egg?
-There is a layer of calcium carbonate over the membrane of the egg. Without deshelling the egg, it would be impossible to allow osmosis to take place as the shell is not permeable. Unlike the shell, the egg membrane is semi-permeable, thus allowing osmosis to take place.
3.Appearance and texture of the egg before and after deshelling.
BEFORE:
The hen egg has a hard shell and it is smooth. It is also opaque.
AFTER:
The egg is smooth soft and translucent, enabling us to see the egg yolk inside the membrane.