Hypertonic, Hypotonic, Isotonic
Hypertonic, Hypotonic, IsotonicFor this experiment, we test the effects of immersing a potato in a hypertonic, hypotonic, and an isotonic solution. The concept we take into account for this experiment is osmosis regulation of water. Osmosis is the movement of water molecules across a semi permeable membrane from a higher concentration of water to a lower concentration of water. This movement follows the concentration gradient. Ψw = Ψs + Ψp, this equation relates the water potential Ψw, together with the solute potential, Ψs and the pressure potential Ψp.
In this experiment, we use different concentration of sucrose solution to control the variable of hypotonic, hypertonic and isotonic. From the results obtained, I can conclude that when the molarity of sucrose is below 0.3M, the potato will increase in length and thus making it into a turgid form feeling hard. From this, we can reason that any sucrose solution with a molarity of less than 0.3M is hypotonic compared to the potato cell. The water molecules will travel from sucrose solution to potato cell.
When we used a sucrose solution with a molarity of 0.3M, there were no changes in the length of the potato. The potato remains flaccid. According to the results, 0.3M is an isotonic solution to the potato cell. For this result, the net movement of water molecules across the semi permeable membrane is zero. The potato feels softer when touched with finger.
When we used sucrose solution with a molarity above 0.3M the potato shortens in length. The cell is now plasmolysed. This happens because the sucrose solution is now hypertonic compared to the potato cell. The water molecules from the potato will travel to the sucrose solution. The potato strip feels very soft when touched with finger.
From all of this above, I can conclude that as the concentration of sucrose solution increases, the length of the potato strips decreases. Therefore, the concentration of sucrose solution is inversely proportional to the length of potato strip.