L3. OSMOSIS

L3: Osmosis

1. INTRODUCTION

Osmosis in the spontaneous movement of solvent molecules trough a semipermeable membrane into a region of higher solute concentracion in the direction that tends to equalize the solute concentracions on two sides. Osmosis is a vital process in biogical systems, as biogical membranes are semipermeable. Water molecules travel trhoug the plasma membrane in order to equilibrate the intra and extra cellular concentracions. When a cell is submerged in water, the water molecules pass trough the cell membrane from an area of low solute concentracion to high solute concentracion. When the extracellular concentracion is hypertonic, water moves out of the cell and the cell becomes flaccid; plasmolysis.

When the extracellular concentracion is hypotonic, water moves inside the cell and it becomes; turgid.

2. OBJECTIVES

- Know about the osmosis phenomena.

- Understand the process of osmosis is plasmatic membranes.

3. MATERIAL

- Egg

- Potato

- Salt

- Distilled water

- Acetic acid

- Spatula

- 600 mL Beacker

- 3 Clock glass

- Pen

- Spoon

- Knife

4. PROCEDURE

EGG: This experiment will be divided in two days,

Under the hard outer shell of a chicken egg is a semipermeable membrane that allows air in moisture to pass though. Becaue water membrane can move into and out of the egg but larger molecules cannot, the semipermeable egg membrane allows for an exploration of concepts of diffusion and osmosis.

1 Day: 

1. Take a 600 mL beaker and put inside the egg

2. Cover the egg with vinegrar and make note of what's happening. 

* Once the egg's shell is removed and the egg is rinsed dry and clean, measure and weigh the egg. Record the dimensions of each egg in a table.

3. Clean the beaker and put the egg inside again.

4. Cover in with distilled water. Make note of the volume of solution inside the beaker.

2 Day: 

5. Left the egg one day in the distilled water. After about a day, carefully remove the egg using a spoon.

6. Measure again the dimensions and record is weight.

7. Make note of the solution volume in the and notice if there has been any difference.

8. Observe the results and write your lab workksheet.

POTATO:

1. Lay out three watch glass.

2. Slice the potato in three parts lenghwise. Each slice must be of 1,5cm thick.

3. Place each slice onto a watch glass and make a hole in the middle of each slice.

4. In the first slice hole, don't put anything. The second fill it with salt and the third with distilled water.

5. Left this preparation 30 minutes and make note of is happening.

5. RESULTS OR OBSERVATIONS

The egg we have observated that when we put the egg with acetic acid the shell what was covering the egg. The egg with the pass of the days it becomes viscous. At the end, the dimension of the egg increased for the hypotonic concentration. The last experiment that we made with potatoes, we thought that in the firs slice,  there would be no reaction. In the second one, with salt the potato will be flaccid, because the water inside will go out because the potato is a hypotonic and the salt is a hypertonic and the potato with distilled water, it becomes turgid. In this case the potato it's a hypertonic and the water hypotonic, and the last potato with distilled water, it becomes turgid. I