Osmosis is a process that occurs at a cellular level that entails the spontaneous net movement of water through a semi-permeable membrane from a region of low solute concentration to an area of high solute concentration in order to equalize the level of water in each region. Involved in this process are hypotonic, hypersonic and isotonic solutions.
A hypotonic solution is one with a lower osmotic pressure, indicating that the net movement of water moves into the said solution whereas a hypersonic solution is one with a higher osmotic pressure, hush the net movement of water will be leaving the hypersonic solution. Lastly, an isotonic solution entails no net movement of water across a semi-permeable membrane as the two substances involved display osmotic equilibrium.
Thus, we can state that there appears to be a negative correlation between Niacin concentration and the mass and length of the potato strips, clearly evident in the above graph which shows an exponential decrease in both mass and length. This can also e initially seen in the post-extraction observations where it is evident that the potato strips immersed in lower Nasal concentration were far more turgid than those immersed in 100% Nasal solution which were flaccid and fragile (see strip- comparison in Fig. 2). This occurrence can be explained through the process of osmosis.
As mentioned in the introduction, a hypersonic solution is one with higher osmotic pressure meaning that the net movement of water leaves the solution. This would explain the physical changes – the increase in mass and length as well as the increase in turgidity – in the potato strips immersed in 100% H2O solutions or owe Nasal-concentration solutions. Since the solution it is submerged in is higher in concentration in water molecules, or hypersonic, the water molecules will diffuse into the area of lower H2O-concentration (the potato strip) in order to achieve equilibrium.
Alternatively, the decrease in mass and length in the potato strips submerged in highly concentrated Niacin solutions can be explained by its immersion in a hypotonic solution. Hypersonic solutions, as mentioned before, are described as those with lower osmotic pressure, indicating that the net movement of water moves into the solution. Therefore, as Nasal solution is sees concentrated in H2O molecules than the potato strips, the decrease in mass and length and loss of turgidity results from the net movement of water leaving the potato strips, which is higher in osmotic pressure, and diffusing into the solution.
Nevertheless, there are several possible sources of error that could have greatly or negligibly affected the outcome of the experiment. First, we must note the varying external factors resulting from an uncontrolled environment – the biology classroom. Primarily, these would include varying temperatures and humidity which could potentially affect the rate of osmosis as increased enrapture results in increased diffusion while increased humidity results in an increased number of water molecules.
Secondly, we must note the human errors involved, for example, miscalculations in experimental preparations. These would include the miscalculation of solutions leading to an inaccurate concentration of Nasal as well as the possibility of impurities in the Nasal concoction in the first place while imprecise cutting of the potato strips could’ve affected the surface area and thus the rate of osmosis.