Introduction
The two driving questions that are asked on the project are "What is osmosis?" and "What happens when the solute concentration of a solution surrounding a cell is different than he internal environment of a cell?". Most of the project is to answer these two questions while doing the experiment and how different outside components affect a carrot,celery, potato,egg and gummy bears.
Materials
The main materials where:
Salt Water
Tap Water
Vinegar
Corn Syrup
Water Beads
Celery and carrot sticks
Gummy Bears
Dialysis tubing
Eggs
Potato
Spoon
Salt
Large cups or beakers
Procedure
Get all the materials and get your safety stuff to do the experiment.
Fill some beakers with fresh water and others with salt water.
Place one carrot in a fresh water beaker and anther carrot in the salt (Do this to every vegetable and the gummy bears except the eggs).
Wait at least a half hour (waiting overnight will have a more dramatic effect), then take the vegetables out of the salt water to see the difference and compare them.
Scientific Principle/ Essential Understanding
Water molecules move across a membrane to higher levels of salt concentration through a process called osmosis.
Animals and plants that live in the ocean usually have a high salt content. On the other hand, animals and plants that are not adapted to salt water may have a low salt content and thus become dehydrated when placed in salt water.
Safety Procedures
Wear goggles when performing demonstrations or experiments.
Also wear gloves.
Also use an apron so you don't get dirty.
Never eat or drink any materials in a lab.
Investigation
What is similar about diffusion and osmosis? What is different?
Diffusion refers to the process by which molecules intermingle as a result of their kinetic energy of random motion.If two solutions of different concentration are separated by a semi-permeable membrane which is permeable to to the smaller solvent molecules, but not to the larger solute molecules, then the solvent will tend to diffuse across the membrane from the less concentrated to the more concentrated solution. This process is called osmosis.
If a solution has a high solute concentration, what must be true about the relative concentration of water?
If the cell is submerged in saltwater, water molecules should move out of the cell and shrink.
If a solution has a low solute concentration, what must be true about the relative concentration of water?
If a cell is submerged in freshwater, water molecules move into the cell and expand.
Why are cut vegetables, such as celery or carrots, placed in water to keep them crisp? What happens if they are put into salt water?
Vegetables such as Carrots and celery are crisp largely because of water (fresh water) trapped within them. If placed in fresh water, the carrot is saltier than the surrounding water, so the water moves into the carrot. This causes the carrot to stiffen if it was previously limp, or preserve its crispness if it was crisp before.
So, if a carrot is placed in very salty water, it will be less salty than the water around it. This causes the water in the carrot to move out of the carrot and into the salt water. The result is that the carrot becomes limp and tastes saltier than before.
PART 2
What adaptations does an organism have to be able to live in salt water, which is hypertonic to their cells?
Organisms living in seawater must have a means of preventing the loss of water from the body to the highly saline environment.
Oil and water do not mix, yet water molecules can easily move into or out cell traveling across the lipid bi layer. What are aquaporins and who discover it?
Aquaporins are integral membrane proteins from a larger family of major intrinsic proteins (MIP) that form pores in the membrane of biological cells.
He 2003 Nobel Prize in Chemistry was awarded jointly to Peter Agre for the discovery of aquaporins, and Roderick MacKinnon for his work on the structure and mechanism of potassium channels. The plasma membranes of a variety of different animal and plant cells contain aquaporins through which water can flow more rapidly inside the cell than by diffusing through the phospholipid bilayer
In what ways they relate to our kidneys?
The Kidneys use active transport (especially of Na) to set up osmotic gradients which is represented in the figure below.The kidney takes advantage of the osmotic pressure difference between tubule fluid and interstitial fluid to move water out of the tubule.By changing the permeability of the collecting duct the kidney is able to make concentrated or dilute urine by osmosis.