Rate of Osmosis Increases as Temperature Increases

Stephanie Parker

Bio 111

Kayla McRobb

05/10/2015

Rate of Osmosis Increases as Temperature Increases

Abstract:

Osmosis assists the cell to reach equilibrium by the diffusion of water to create an isotonic environment. This experiment was preformed to determine whether temperature influences the rate at which water is diffused though the membranes. We hypothesized that the rate of osmosis would increase with a higher temperature. We used three different osmometers with a 40% sugar solution was used to create an environment, 39° C, 23° C, and -10° C, in which dialysis was used to replicate a cells osmotic rate. We recorded the data every minute. We then created a scatter plot with a line that best fit all three slopes which told us the rate in which the sucrose solution rose The results of the experiment supported the hypothesis that osmosis had an increased at a 1.38 cm/min rate with a higher temperature environment, the room temperature will reach the isotonic state the second quickest at a .52 cm/min rate, and the -10° C iced water will reach the isotonic state the slowest at a .45 cm/min rate. Our hypothesis was supported because the higher temperature lead to higher osmostic rates.

Introduction:

        Our body’s smallest units of life, cells, undergo a process called osmosis, the diffusion, or passive movement of molecules along a concentration gradient that regulates from higher to lower regions, of water across a selectively permeable membrane, a type of membrane that allows certain molecules or ions to pass through it by means of active or passive transport, to carry out its processes for life (Urry 101). The passive movement of water is crucial to maintain homeostasis, the tendency of an organism or cell to regulate its internal conditions, and tonicity, a state of normal firmness or functional readiness, of the cells. Tonicity is the ability of a surrounding solution to cause a cell to gain or lose water (Campbell 101). The selectively permeable membrane rejects ions and other molecules while allowing water to pass through to equalize the cell.

Temperature directly influences the osmotic pressure of the solution. It has been recognized that the increase of temperature on the osmotic rate of dialysis. The increase in temperature raises the osmotic pressure of the solution. Temperature reduces the amount of energy consumption while it enhances the recovery rates and permeate flux (Phuntsho et al. 2012). Temperature has a significant role in the rate and increasing the performance of osmosis.

The purpose of this experiment is to investigate the rate at which the solvent, water, diffused across a semipermeable membrane. It was hypothesized that the osmotic rate depends on the temperature of water, and that an increase of temperature will lead to an increase of the osmotic rate. It was predicted that the 39° C would reach an isotonic, having the same osmotic pressure, the quickest at a rate of 1.38 cm/min, the 23° C room temperature (control) will reach the isotonic state the second quickest at a .52 cm/min rate, and the -10° C iced water will reach the isotonic state the slowest at a .45 cm/min rate.

Methods:

        The experiment began we filled three dialysis bags that were tied to the end of an osmometer tube, an instrument used to measure osmotic pressure. Three beakers were placed into temperature controlled areas, 39° C, 23° C, and -10° C. The first bag was placed into the heated beaker, the room temperature (control) bag was placed second, and lastly the chilled bag was placed. The original sucrose level was marked on the tube with tape so measurements were accurately taken. Every minute the rate of increase of diffusion in millimeters was recorded for twenty minutes. The rate was found by. The rate was used to create a scatter plot.[pic 1]