Osmosis as a Phenomenon in The Life-preserving Functions

Osmosis (the transportation of a solvent from a lower concentration to a higher one through a semipermeable membrane) is a fundamental concept in the study of biology providing the primary means by which water is transported into and out of cells. The importance of this phenomenon lies in the great number of life-preserving functions it carries out. Examples of this are the preservation of fruit and meat, assisting plants in receiving water as well as kidney analysis. Plants such as the watermelon depend on the phenomenon of osmosis to carry out day-to-day activities. An example would be the transportation of water from the plants’ roots to their leaves. Therefore, after researching the uses of this phenomenon I started wondering if it impacts important characteristics of plant tissues such as their mass. The reason why after careful deliberation, the watermelon (Citrullus lanatus) was chosen as the chief plant to investigate the effects of osmosis on the mass of plant tissues, is the fact that it has three distinctive parts. Therefore, it would be interesting to find out whether the trend would be the same in all three parts or if each part’s mass was going to be affected differently by osmosis. What is more, I chose watermelon because of the wide range of life-preserving functions it has.

More specifically, not only does is useful to quench one’s thirst but it can also apply to stop the inflammations that contribute to conditions such as asthma, diabetes and colon cancer. In order to carry out my experiment more effectively, I decided to perform osmosis experiments on all the three different parts of the watermelon. The reason for that is that the tissues of the watermelon parts vary in size, thickness, and mass and would enable me to conduct a much wider and more diversified study of the rate of osmosis in watermelons. The sucrose concentrations were chosen according to the optimum amount of sucrose that a watermelon usually has.

After deducing the optimum, I decided to include 2 concentrations smaller and 2 larger than it. This would help me determine the impact of the phenomenon of osmosis in watermelon tissues more safely, since the range of data would be larger. Research Question: How does the phenomenon of osmosis affect the mass of the tissues of the different parts of the watermelon after their immersion to sucrose solutions of different concentration? Water temperature All test beakers containing the watermelon tissues immersed in sucrose concentrations were left in an air-conditioned room over the period of 4 hours set at the temperature of 22°C, which was monitored every hour to ensure that it remained constant Water Volume: 400 cm3 The 400 cm3 of water was measured from the same measuring cylinder Room Temperature The experiment took place in an air-conditioned room over the period of 4 hours set at the temperature of 22°C, which was monitored every hour to ensure that it remained constant Time of Immersion (Duration): 4 hours The exact time of immersion (4 hours) was kept using the same watch throughout the experiment Size and shape of watermelon tissues Each watermelon tissue was cut to the same length (3cm) (measured using the same ruler) then weighed (on the same weighing scale with fresh pieces of paper towel replaced each time) to ensure they weigh the same Source of watermelon All watermelon tissues came from the same watermelon

Materials

• 1) 1 and a half watermelon
• 2) 1 volumetric cylinder
• 3) 205,2 grams of sucrose
• 4) 15 beakers (500 cm3)
• 5) 1 spoon
• 6) 1 knife
• 7) Tap water
• 8) Electronic weighing scale
• 9) Ruler
• 10)Paper towel
• 11)Stopwatch

Method-Procedure

The watermelon will be first separated into its green part (the exocarp), its white part (the endocarp) and its red part (the mesocarp). Then, it will be cut into thin slices and these are going to be measured (initial mass) Then they are going to be placed in different sucrose concentrations. The different sucrose concentrations will be created by calculating the specific percentage of sucrose in a set amount of water and then after weighing the amount of sucrose, mixing it with the water. Each sucrose concentration (0%, 1.5%,3.6%,5%,7%) will be immersed in 400 ml of water and all three parts of the watermelon are going to be dipped in all 5 sucrose concentrations, meaning that 45 slices of watermelon and 15 beakers will be required. Then, the different watermelon tissues will be left immersed in the sucrose concentrations for 4 hours. After that time has passed, the slices will be once more observed and weighed to see if there are any changes in mass (increase or decrease), in order to try to show the effects of the phenomenon of osmosis in different watermelon tissues.