Introduction to Cell & Molecular Biology (BIOL121) - Dr. S.G. Saupe (; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321

Study Guide for Lipids & Membranes

Goal:  The goal of this unit is to understand how water and solutes move into/out of cells.

Learning Objectives:  Upon completion of this unit the student should be able to:

  1. describe the chemical composition of the three main classes of lipids (triacylglycerides, phospholipids, steroids)

  2. describe the structure and function of the membrane.

Terms/ConceptsCan you use these in a sentence?  Or, prepare a concept map with them?

  • cell (or plasma) membrane

  • lipid, oil, fat

  • hydrophobic

  • hydrophilic

  • amphathic

  • hydrocarbon

  • fatty acid

  • steroid

  • phospholipids

  • triglyceride (triacylglyceride)

  • liposome

  • selectively permeable

  • saturated

  • unsaturated

  • fluid mosaic model

  • unit membrane model

  • integral (or transmembrane) protein

  • peripheral protein


  1. Compare and contrast fat, oil, and waxes

  2. What the the components that form a triacylglyceride?  By what type of reaction are TAG's formed?  If given the structures for these starting materials can you draw a final TAG? 

  3. What is the function of TAG's?

  4. How are phospholipids simlar to TAG�s?  How do they differ? 

  5. Phosopholipids are drawn like two tailed sperm?  What does the circle and the tails represent?

  6. Which parts of the phospholipids are hydrophobic and which are hydrophilic?

  7. What is a steroid and what are their function? 

  8. Describe the functions for lipids in cells/organisms.

  9. Describe the chemical structure of a membrane.  Identify the current model for the membrane?  What was the original model.  Explain how freeze fracture images provided evidence to support the new models. 

  10. In the Fluid Mosaic model, what does the word �fluid' refer to?  'Mosaic'?

  11. Identify the functions of the cell membrane.

  12. Explain how making mayonnaise was analogous to a membrane? Can you explain the Gink and GO dialog?

  13. What is liposome?

  14. What factors influence membrane fluidity? (hint, saturation, cholesterol, temperature)

  15. Draw a diagram of the structure of the fluid mosaic model and label the following phospholipids, bilayer, integral protein, peripheral protein, glycoprotein, glycolipid, components.

  16. Check out the membrane questions that are posted on line.

  17. Can you answer the Spuds McSaupe study sheet.

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Last updated: July 14, 2009     � Copyright by SG Saupe