Diffusion and Osmosis
Diffusion
And
Osmosis
Abstract
In this Diffusion and Osmosis lab a total of three experiments were performed. For experiment 5.1 we investigate diffusion through a selectively permeable membrane and the many factors that influence the rates of diffusion. In experiment 5.2 we investigate both animal and plant cells in different molar solutions and the different osmotic behaviors within the cells. In experiment 5.3 we test the osmolarity of plant cells through the usage of potato tuber cells.
In experiment 5.1 in order to observe diffusion we examine the Brownian movement by observing carmine on a wet mount slide, and by using dialysis tubing, we investigate the selective permeability to reducing sugar, glucose, starch, and iodine potassium iodine. In experiment 5.2 we use samples of ox blood and Elodea plant to observe the net flow of water from the surrounding solution into the cells. In experiment 5.3 in order to estimate the osmolarity of the potato tuber cells we use the methods of change in weight and change in volume.
In experiment 5.1 while observing the wet mount, the Brownian movement of the carmine particles are never ending and show no pattern. While investigating the permeability of the dialysis tubing through the Benedict’s test, the solution inside of the bag (glucose), was originally clear, but after the Benedict’s test turned a strong orange color, finally ending with a final color of dark blue-black. In experiment 5.2 while observing the ox blood under the microscope the cells underwent either lysis or shriveled up. When observing the Elodea cells in distilled water and separately in salt water, the appearance and condition of the cell drastically changed. When the Elodea cell was placed into the distilled water, the cell became swollen and underwent lysis. However, when the Elodea cell was placed into salt water, the cell shriveled up and appeared bumpy. In experiment 5.3 when placing the potato segments into different molarities of
And
Osmosis
Abstract
In this Diffusion and Osmosis lab a total of three experiments were performed. For experiment 5.1 we investigate diffusion through a selectively permeable membrane and the many factors that influence the rates of diffusion. In experiment 5.2 we investigate both animal and plant cells in different molar solutions and the different osmotic behaviors within the cells. In experiment 5.3 we test the osmolarity of plant cells through the usage of potato tuber cells.
In experiment 5.1 in order to observe diffusion we examine the Brownian movement by observing carmine on a wet mount slide, and by using dialysis tubing, we investigate the selective permeability to reducing sugar, glucose, starch, and iodine potassium iodine. In experiment 5.2 we use samples of ox blood and Elodea plant to observe the net flow of water from the surrounding solution into the cells. In experiment 5.3 in order to estimate the osmolarity of the potato tuber cells we use the methods of change in weight and change in volume.
In experiment 5.1 while observing the wet mount, the Brownian movement of the carmine particles are never ending and show no pattern. While investigating the permeability of the dialysis tubing through the Benedict’s test, the solution inside of the bag (glucose), was originally clear, but after the Benedict’s test turned a strong orange color, finally ending with a final color of dark blue-black. In experiment 5.2 while observing the ox blood under the microscope the cells underwent either lysis or shriveled up. When observing the Elodea cells in distilled water and separately in salt water, the appearance and condition of the cell drastically changed. When the Elodea cell was placed into the distilled water, the cell became swollen and underwent lysis. However, when the Elodea cell was placed into salt water, the cell shriveled up and appeared bumpy. In experiment 5.3 when placing the potato segments into different molarities of
References: * Lodish, H; Berk, A; Kaiser, C; Scott, M; Ploegh, H, Bretscher, M. 2007. Molecular Cell Biology, Freeman, United State of America. * Wayne, R. 2009. Plant Cell Biology: From Astronomy to Zoology, Academic Press, United States of America. * Lewis, M. 1997. Diffusion, Osmosis, and ATP. Pp. 176-182 in Mallinson, J et al. eds, Integrated Science: Horizons (6th edition), Ginn, New Jersey. * Miller, S. 2006. Animal Cells and Their Function. Pp. 126-148 in Castro, B et al. eds, Zoology (7th edition). McGraw-Hill, Texas * Morgan, G; Carter, M; Dickey, J. 2010. Investigating Biology, Pearson, United States of America. * Cambell, N; Reece, J. 2007. Biology (8th edition), Cummings, United States of America.