BIO 204 Week2 Applying the Concept of Membrane Transport Presentation

Content

Scenario 1: Semipermeable membrane bag containing a 30% sugar solution is placed in a beaker of pure water.Scenario 2: Cell membrane of a nerve cell Scenario 3: Elodea leaf is placed in a 2% salt solutionScenario 4: Cell engulfs debris from outside itselfScenario 5: Cell makes protein that is headed for a different location within the plant

Introduction

Intercellular and extracellular interaction with particles or molecules are facilitated by several mechanisms. They include osmosis, diffusion , active transport, endocytosis, and exocytosis. In this presentation we will explore five scenarios giving the form of transport and related details.

Scenario 1: Semipermeable membrane bag

When a semipermeable membrane bag containing a 30% sugar solution is placed into a beaker of pure water is example of osmosis.

Fig 1. Example of Osmosis of a concentrate of a sugar solution through a semipermeable membrane. (Pal, Kanti)

Scenario 2: Cell membrane of a nerve cell

When the cell membrane of a nerve cell keeps 14 times as much sodium outside as it does inside is an example of diffusion.

Fig 2. Example of Diffusion in a cell of a Glucose Molecule. (Yahoo Images, 2014)

Scenario 3: Elodea leaf is placed in 2% salt solution

When an Elodea leaf (a freshwater plant used in fish tanks) is placed in a 2% salt solution is an example of osmosis.

In the following experimental set up, 10% NaCl is hypotonic to the Elodea cells.imc02.hccs.edu

Scenario 4: Cell engulfs debris

This is an example of endocytosis – the uptake of extracellular material in vesicles formed from the plasma membrane. (Cooper, GM)Bacteria binds with the plasma membrane by means of the pseudopodiiumLarge intracellular vesicles called phagosome binds with lysosome to digest the bacteria Part of the digested membrane is later recycled to the plasma membrane.

The Cell: A Molecular Approach (http://www.ncbi.nlm.nih.gov/books/NBK9831/

Scenario 5: Cell makes protein

This is an example of exocytosis – the process of releasing molecules packaged in membrane bound vesicles via the plasma membrane. (Alberts B, Johnson A, Lewis J,)The secretory pathway begins in the endoplasmic reticulum before moving towards the Golgi complex.Leaving the Golgi complex, the protein moves outward to the plasma membrane to be used in other parts of the plant.

Conclusion

The transfer of materials across the membrane as depicted by the five scenarios included:OsmosisDiffusionEndocytosisExocytosis

References

Mauseth, J. D. (2014). Botany: An Introduction to Plant Biology (5th ed.). : Jones and Bartlett.Yahoo Images, 2014. Diffusion. Retrieved from the World Wide Web on December 11, 2014. https://images.search.yahoo.com/search/images;_ylt=AwrBT9PdxolU3Q8AbiRXNyoA;_ylu=X3oDMTB0MmRpamVqBHNlYwNzYwRjb2xvA2JmMQR2dGlkA1ZJUDQ5NV8x?_adv_prop=image&fr=yfp-t-455&va=diffusionPal, Kanti. Osmosis. Retrieved from the World Wide Web on December 11, 2014. https://images.search.yahoo.com/search/images;_ylt=A0LEVzWu0olUEtcAefpXNyoA?p=Osmosis&fr=yfp-t-455&fr2=piv-webCooper, G. (2000). The Cell a Molecular Approach. The 2nd Edition., http://www.ncbi.nlm.nih.gov/books/NBK9838/Cooper, GM. The Cell: A Molecular Approach. 2nd edition. Sunderland (MA): Sinauer Associates; 2000. Endocytosis. Available from: http://www.ncbi.nlm.nih.gov/books/NBK9831/White blood cells fight infection. (2015). In The Hutchinson unabridged encyclopedia with atlas and weather guide. Abington, United Kingdom: Helicon. Retrieved from http://search.credoreference.com/content/entry/heliconhe/white_blood_cells_fight_infection/0Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Chapter 13, Intracellular Vesicular Traffic. Available from: http://www.ncbi.nlm.nih.gov/books/NBK21045/American Society of Plant Physiologists. (April, 19999) The Plant Cell, Vol. 11,p.646. Retrieved from: www.plantcell.org