Osmosis And Diffusion Lab Report

One purpose of the experiment was to gain an understanding of diffusion and osmosis, specifically in context of a plant or animal cell reaction to an isotonic, hypotonic, or hypertonic solution. Another objective was to understand the nuances of simple diffusion, facilitated diffusion, and active transport and to explicate the characteristics affecting the rates of diffusion. The next objective was to be able to explicate the partition coefficient and its influence on hemolysis. The final objective was to properly use a pipette (Spilios, 2015).
Hemolysis occurred despite the red blood cells being in isotonic solution (0.3 M) due to the permeability of the cellular membrane. As the molecules from the solution surrounding the red blood cell
This did not support the hypothesis that the influence of the increasing partition coefficient would dominate over the increase in molar volume across these molecules, causing a decrease in hemolysis times from methanol to ethanol to propanol. Experiments have shown that the membrane permeability of short-chain alcohols, like the ones studied in this lab, has a chain-length dependency. As the length increases and the molecules gain more CH2 groups, the membrane permeability increases (Hung et. al., 2004). However, the results were inconclusive on to this end, because the hemolysis times for the alcohols were so fast that their hemolysis times were not significantly different. This may be due to the fact that the hemolysis times occurred so quickly that the experimenters were unable to measure the hemolysis times accurately and precisely. The red blood cell membrane permeability of methanol was shown to be 3.7 x 10-3 cm/s; ethanol was shown to be 2.1 x 10-3 cm/s; propanol was shown to be 6.5 x 10-3 cm/s (Somnez et. al., 2013). Although the results are not supportive of the alcohol data alone for this experiment, they do reflect the relationship between the alcohols and the other nonelectrolytes tested. For example, urea has a permeability of (1.16 ± 0.05) x 10-3 cm/s, which is very close to the alcohols’ permeability. Consistently, urea has a similar hemolysis time as the
The results do not support the hypothesis that due to the lower partition coefficient of urea and in spite of its lower molar volume, urea would yield a slower hemolysis time than ethylene glycol. These results, however, do support the work of Mayrand et. al. (1983), who performed an experiment testing the inhibiting abilities of urea on ethylene glycol and osmotic permeability and the inhibiting abilities of ethylene glycol on ethylene glycol permeability. The results of their experiment revealed that urea has a permeability of (1.16 ± 0.05) x 10-3 cm/s while ethylene glycol has a permeability of (4.8 ± 0.2) x 10-4 cm/s (Mayrand et. al., 1983). The permeability of urea is much higher than that of ethylene glycol, which is consistent with urea having a significantly lower hemolysis rate than ethylene