Osmosis Diffusion Investigation Lab Report

Osmosis/Diffusion Investigation 4 Lab Report

Cappy Pierce

November 6th 2015

Labs done with: Ethan Anderson, Emily Levin, and Logan Lucas

Instructed by: Mrs. Nyland

Abstract:

Diffusion and osmosis are necessary for the efficient transport of substances in and out of living cells. Diffusion is the most common and effective transportation process between cells and their surroundings, the movement of a substance along a concentration gradient from high to low, allowing essential nutrients and compounds to be transported without expending energy. Osmosis is a special kind of diffusion, specific to water. In order to observe diffusion and osmosis in real and artificial cells, a series of experiments was put together to observe how the surface area to volume ratio effects the rates of diffusion by using agar in different shapes with different ratios, next the rate of diffusion due to tonicity was observed using different solutions with different tonicities. And lastly live plant cells were submerged in different solutions with varying water potentials to observe how was potential effects the rate of osmosis and diffusion. It was concluded that the larger surface area to volume ratio, the faster rate of diffusion, the hypertonic solutions caused water to leave a cell and the hypotonic solutions allowed water to enter a cell, and that water potential will move from high to low in an attempt to maintain equilibrium.

Purpose/Discussion of Concepts:

The purpose of the series of experiments in the lab was to in part one, see the relationship between surface area, volume, and the rate of diffusion, diffusion is the process of substances crossing the cell membrane). In part two it was to create manmade “cells” to help discover hypotonic (when t...

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...ond sets of data concluded that sucrose, glucose, and salt are hypotonic solutions that will remove water from a cell due to their tonicity. In the final part of the lab, results concluded that water potential moves along its concentration gradient (high to low) in an attempt to maintain equilibrium. It was determined that the orange and green solutions were hypotonic as they added water to the cells, whereas the blue, red, purple and yellow solutions were hypertonic as they sucked water from the cells.

References:

1)"Big Idea 2: Cellular Processes: Energy and Communication." AP Biology Investigative Labs: An Inquiry-based Approach. Ed. The College Board. New York: College Board, 2012. 51-61. Print.

2)Campbell, Neil A., and Jane B. Reece. Biology. San Francisco, CA: Benjamin Cummings, 2008. Print.

3)"Water Potential." Bozemanscience. N.p., n.d. Web. 12 Nov. 2015.