Scientific Inquiry: Bubbles, Skittles, and Celery Jen, Larry, and Laura Jefferson Elementary School Bubbles Question: Celery Skittles In what ways is a bubble like a cell membrane? Hypothesis:We predict that bubbles are similar to cell membranes because they are semi-permeable and flexible. Experiment:We created a frame by connecting flexible straws into a rectangular shape. In a baking tin we combined 900 ml of H20, 100 ml of dish soap, and 25 ml of corn syrup. We dipped the straw rectangular frame into the bubble solution creating an imitation of a cell membrane. Next we placed a dry thin piece of string onto the “cell membrane”, then we placed a string soaked in the “bubble” solution onto the “cell membrane.” Observations:When we placed the dry string onto the “cell membrane” we observed that the “cell membrane” ruptured. However when we placed the string soaked in the bubble solvent the “cell membrane” accepted the string, allowing the string to move freely within the straw framework. Conclusion:We concluded that the string soaked in the bubble solvent acted as a lipid bi-layer, forming a continuous barrier around the cells “cell membrane.” Question:How do vinegar vs. oil effect the rate of diffusion on a skittle coating. Hypothesis:We predict that a skittle in vinegar will diffuse at a greater rate than a skittle in oil. Experiment: We filled one petri dishes with 15 ml of vinegar and a second petri dish with 15 ml of oil. We then placed each petri dish over a concentric circle diagram. Next we placed an orange skittle in the center each of the two petri dishes. Observations: Conclusion: We concluded vinegar diffused at a rate of cm/sec while oil diffused and a rate of cm/sec. We believe that the skittle did not diffuse in the oil because the oil had a higher concentration of solute. Question:What effect does light have on transpiration (xylem flow)? Hypothesis:We predict that the absence of light will decrease the rate of transpiration when compared to transpiration where light is present. Experiment: We filled two beakers each with 150 ml of H2O and added two drops of red food coloring into each beaker. Next we cut off the bottom ends of the celery making them similar in length. We then placed each stalk of celery in the red H2O solution. Next we placed one fo the beakers in a cabinet where no light was able to reach the celery stalk. The second beaker was placed under a 40 watt lamp. Each beaker remained in it’s location for 48 hours. Observations:When we examined both beakers/celery we found that the volume of H2O in the beaker under the light decreased by 50 ml. The volume of the water in the beaker that remained in the cabinet stayed the same (150 ml). When we examined the distance the red dye traveled we found the celery stalk under the lamp traveled a distance of 8 cm. While the red dye in the celery stalk with the absence of light traveled 1.8 cm. Conclusion: We concluded that the presence of light directly effects transpiration (xylem flow).