The objective of this experiment was to test the effect of a specialized type of diffusion called osmosis, “which involves in selective transport of water molecules across a selectively permeable membrane” (Lab Manual 2nd edition). It was hypothesized that osmosis will occur when there is an uneven distribution of solute in a solvent. The more abundant the solute is in solvent, the higher the rate of osmosis through the diffusion gradient forming a hypertonic or hypotonic solution. Solvent with equal or no solute forms an isotonic solution. Throughout this lab, data was collected and compiled to analyze these effects across selectively permeable membranes. The results indicated that the water molecules indeed move from high concentration to low concentration, while solutes do the same if the membrane is permeable to them. This was evident through our experiments in which membrane permeability was tested in living Elodea plant cell, which was placed in 3 different solutions, from distilled water to 15% NaCl solution, to test how the cell would react to it. In addition, dialysis tubes were used in water and maltose solution to test for osmosis, since they have an artificially permeable membrane closely resembling a human cell.
CONDITIONS/TIME
0 MIN
10 MIN
20 MIN
30 MIN
40 MIN
50Min
WATER IN BAG; MALTOSE IN BEAKER
13 g
12g
11.5g
11g
10g
8g
Orange
WATER IN BAG; WATER IN BEAKER
11g
11g
10.5g
10g
11g
10.5g
Blue
MALTOSE IN BAG; WATER IN BEAKER
10g
10g
10.6g
10.8g
10.6g
10.5g
Orange
MALTOSE IN BAG; MALTOSE IN BEAKER
12g
13g
12.5g
13g
12.5g
12.5g
Orange
Four dialysis bags were prepared for this experiment. The first bag filled with distilled water and submerged in 40% maltose solution significantly decreased in weight as time progressed. This indicated that water