Biology Osmosis Lab Report
Osmosis Lab Report
by
Evan Gerber
Claire Cambron
First Lab Report
Wednesday 10:30am
February 20, 2013
Theresa Gburek
Abstract
The major objective of the experiment was to test the effect of the concentration gradient on the diffusion rate. It was hypothesized that the greater the stronger the concentration gradient, the faster the rate of diffusion would be. To test this, dialysis tubes were submerged in different concentration fructose solutions. We weighed the tubes at specific time intervals to measure the rate of diffusion of water in each different solution. The results illustrated that increased concentration gradient increases the rate of diffusion of water in the tubes. We concluded that as concentration of the solution increases, the diffusion rate of water out of the tubes increases proportionally.
Introduction
The cell membrane serves many purposes, such as regulating the transport of material into and out of the cell. However, not all macromolecules enter the cell through the same way. The cell is comprised of mostly cytoplasm and floats in an aqueous, watery medium. The cell’s membrane functions as a hydrophobic phospholipid bilayer barrier between both aqueous regions. The heads of the phospholipids are hydrophilic, and thus face the aqueous regions to the inside and outside of the cell, while the hydrophobic tails face inside. Because the inner region of the cell membrane is hydrophobic, macromolecules that are also hydrophobic pass through it the most easily (Sadava 107).
The cell membrane is selectively permeable, meaning that only certain substances are allowed to pass through. There are two types of transport across the membrane: passive and active transport. Passive transport does not require energy, and active transport requires outside energy, often in the form of ATP, to move substances across the membrane (Sadava 114). For this lab, the focus was on passive transport, specifically the passive process of osmosis. Osmosis
by
Evan Gerber
Claire Cambron
First Lab Report
Wednesday 10:30am
February 20, 2013
Theresa Gburek
Abstract
The major objective of the experiment was to test the effect of the concentration gradient on the diffusion rate. It was hypothesized that the greater the stronger the concentration gradient, the faster the rate of diffusion would be. To test this, dialysis tubes were submerged in different concentration fructose solutions. We weighed the tubes at specific time intervals to measure the rate of diffusion of water in each different solution. The results illustrated that increased concentration gradient increases the rate of diffusion of water in the tubes. We concluded that as concentration of the solution increases, the diffusion rate of water out of the tubes increases proportionally.
Introduction
The cell membrane serves many purposes, such as regulating the transport of material into and out of the cell. However, not all macromolecules enter the cell through the same way. The cell is comprised of mostly cytoplasm and floats in an aqueous, watery medium. The cell’s membrane functions as a hydrophobic phospholipid bilayer barrier between both aqueous regions. The heads of the phospholipids are hydrophilic, and thus face the aqueous regions to the inside and outside of the cell, while the hydrophobic tails face inside. Because the inner region of the cell membrane is hydrophobic, macromolecules that are also hydrophobic pass through it the most easily (Sadava 107).
The cell membrane is selectively permeable, meaning that only certain substances are allowed to pass through. There are two types of transport across the membrane: passive and active transport. Passive transport does not require energy, and active transport requires outside energy, often in the form of ATP, to move substances across the membrane (Sadava 114). For this lab, the focus was on passive transport, specifically the passive process of osmosis. Osmosis
Cited: Bodalo-Santoyo, A. "Application of Reverse Osmosis to Reduce Pollutants Present in Industrial Wastewater." ScienceDirect.com. Elsevier Properties, n.d. Web. 19 Feb. 2013. Brace, R. A. "Result Filters." National Center for Biotechnology Information. U.S. National Library of Medicine, n.d. Web. 19 Feb. 2013. Farzin, Manoush. Bio 181: General Biology for Majors I. Tempe: Alternative Print & Copy, 2013. Print. Sadava, David E. Life: The Science of Biology. 9th ed. Sunderland, MA: Sinauer Associates, 2011. Print. Wijmans, J. G., and R. W. Baker. "The Solution-diffusion Model: A Review." Journal of Membrane Science 107.1-2 (1995): 1-21. Sciencedirect.com. Elsevier Properties. Web. 19 Feb. 2013.