Grapes in Water

[Feelings]

Thanks for helping me do my biology homework

If I poke a hole in a grape (with stem attached), and drop the grape in a cup of water, what will happen to this water over time? And the grape?

What if I drop a grape (with stem attached) into a glass of water?

Raisin in water? I know it rehydrates but there should be little holes in the raisin from the shrivelling shouldn't there? Won't the stuff in the raisin diffuse into the water?

 

[IndigoSensor]

Well. I am going to guess that the grape will sink. I don't know if it will, but I am going to assume it will anyway. As a grape is mostly water, with others solids in it, it can be seen as an enlarged cell. Since cells contain different levels of ionic and covalent solute concentrations, the overall density of the solution in the grape is going to be quite different from the pure water. Now, since a small hole in the grape will allow liquid in the cup to enter, osmosis will occur. This will thus change the concentration of the solution in the grape (I am assuming less concentrated), thus lowering the density of the solution. Lower density till the point where it reaches an equalibrium, the grape will then begin to float in the middle of the glass after a few hours (after a slight bit of stirring), instead of resting solidly on the bottom.

 

[Flavus Aquila]

Well. I am going to guess that the grape will sink. I don't know if it will, but I am going to assume it will anyway. As a grape is mostly water, with others solids in it, it can be seen as an enlarged cell. Since cells contain different levels of ionic and covalent solute concentrations, the overall density of the solution in the grape is going to be quite different from the pure water. Now, since a small hole in the grape will allow liquid in the cup to enter, osmosis will occur. This will thus change the concentration of the solution in the grape (I am assuming less concentrated), thus lowering the density of the solution. Lower density till the point where it reaches an equalibrium, the grape will then begin to float in the middle of the glass after a few hours (after a slight bit of stirring), instead of resting solidly on the bottom.

Live plant cells have large vacuoles of gas - so I think it will eventually float, as Indigo said.

The purpose of the experiment, I'm guessing, is about osmosis. The burst grape will leech sugar into the water, because most grapes are completely saturated with water and cannot expand. If it does, it may have the effect of kind of turning the grape inside-out. On the other hand, the raisin should swell without leeching too much sugar because qualitatively, grapeskins seem much more permeable to water than they are to sugar.

 

[christmas]

grapey explosion? will you come back and tell us, pierce?