Lab Report
Laboratory Report
The Plasma Membrane
I. Introduction
The Plasma membrane is the edge of life, the boundary that separates the cell from its surroundings. It controls the traffic of materials in and out of the cell. (Reece, 2011). It is incredibly thin that is very vital in maintaining the integrity of the cell. Not only does the plasma membrane bind the other organelles, it also forms a dynamic structure which gives them their remarkable activity and selectivity. (Hickman, 2008).
Diffusion is the movement of particles from an area of higher concentration to a lower concentration until they reach Equilibrium. (Hickman, 2008).Osmosis happens when water diffuses across the membrane from the region of lower solute concentration (higher free water concentration) to that of higher solute concentration (lower free water concentration) until the solute concentrations on both sides of the membrane is equal. (Reece, 2011). Active Transport is the type of transport of molecules where energy is supplied to the transporter system to transport in the direction opposite to a concentration gradient. (Hickman, 2008).
The objectives of our experiments are to characterize the plasma membrane and to differentiate diffusion, osmosis and active transport.
II. Methodology
A. Structure of the Plasma Membrane
i. We mixed 5 ml of water and cooking oil into a test tube by shaking it. Then we observed the mixture as it settles for five minutes. We shook the test tube again and took a sample into a slide before it settled. We observed it under the LPO of the compound microscope. ii. We placed cooking oil into a Petri dish, and dropped an egg solution into it. We observed it for a formation of a membrane, then puncturing it. iii. We placed the evaporated milk in a beaker until it is ¾ full and heat it. We then observe the formation of milk skin at the top. Second is to remove the milk skin and heat again. Observe what happens.
B. Selective action of the Plasma Membrane
i. We
The Plasma Membrane
I. Introduction
The Plasma membrane is the edge of life, the boundary that separates the cell from its surroundings. It controls the traffic of materials in and out of the cell. (Reece, 2011). It is incredibly thin that is very vital in maintaining the integrity of the cell. Not only does the plasma membrane bind the other organelles, it also forms a dynamic structure which gives them their remarkable activity and selectivity. (Hickman, 2008).
Diffusion is the movement of particles from an area of higher concentration to a lower concentration until they reach Equilibrium. (Hickman, 2008).Osmosis happens when water diffuses across the membrane from the region of lower solute concentration (higher free water concentration) to that of higher solute concentration (lower free water concentration) until the solute concentrations on both sides of the membrane is equal. (Reece, 2011). Active Transport is the type of transport of molecules where energy is supplied to the transporter system to transport in the direction opposite to a concentration gradient. (Hickman, 2008).
The objectives of our experiments are to characterize the plasma membrane and to differentiate diffusion, osmosis and active transport.
II. Methodology
A. Structure of the Plasma Membrane
i. We mixed 5 ml of water and cooking oil into a test tube by shaking it. Then we observed the mixture as it settles for five minutes. We shook the test tube again and took a sample into a slide before it settled. We observed it under the LPO of the compound microscope. ii. We placed cooking oil into a Petri dish, and dropped an egg solution into it. We observed it for a formation of a membrane, then puncturing it. iii. We placed the evaporated milk in a beaker until it is ¾ full and heat it. We then observe the formation of milk skin at the top. Second is to remove the milk skin and heat again. Observe what happens.
B. Selective action of the Plasma Membrane
i. We
References: Cell project. Retrieved on July 4 2013 from, http://www.pleasanton.k12.ca.us/avhsweb/thiel/biosci/difflab.html Cooper GM. (2000).The Cell: A Molecular Approach (2nd edition). Sunderland (MA): Sinauer Associates, retrieved on July 3, 2013 from, http://www.ncbi.nlm.nih.gov/books/NBK9928/ Hickman, C. et al. (2008). Integrated Principle of Zoology (14th edition). Boston: McGraw-Hill. Red cell fragility - Osmotic Hemolysis. Retrieved on July 4 2013 from, http://www.medicine.mcgill.ca/physio/vlab/bloodlab/eryfrag1_n.htm Reece, J.B. et al. (2011). Campbell biology (9th edition). Harlow: Pearson Education, Inc. Transport across- Membrane Lab, Retrieved on July 4 2013 from, http://course1.winona.edu/mgarbrecht/Membrane%20Lab.pdf Why Does Milk Form a Skin When it is Heated?, Retrieved on July 4 2013 from, http://www.wisegeek.org/why-does-milk-form-a-skin-when-it-is-heated.htm