Chapter 7: Membrane Structure and Function
Concept 7.1 Cellular membranes are fluid mosaics of lipids and proteins
1. The large molecules of all living things fall into just four main classes. Name them. Explain what is meant when we say a molecule is amphipathic.
3. In the 1960s, the Davson-Danielli model of membrane structure was widely accepted. Describe this model and then cite two lines of evidence that were inconsistent with it.
4. Who proposed the fluid mosaic model of membrane structure? When? Describe this model.
5. What is meant by membrane fluidity? Describe the movements seen in the fluid membrane. 6. Describe how each of the following can affect membrane fluidity: decreasing temperature
phospholipids with unsaturated hydrocarbon chains
cholesterol
7. Membrane proteins are the mosaic part of the model. Describe each of the two main categories: integral proteins
peripheral proteins
8. Use Figure 7.9 to briefly describe major functions of membrane proteins.
Function Description
Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercellular joining
Attachment to cytoskeleton and ECM
9. Membrane carbohydrates are important in cell-cell recognition. What are two examples of this?
Distinguish between glycolipids and glycoproteins.
Label the following structures: glycolipid, glycoprotein, integral protein, peripheral protein, cholesterol, phospholipid, ECM fibers, cytoskeleton microfilaments, integrins (go back to Chapter 6)
Concept 7.2 Membrane structure results in selective permeability
Distinguish between channel proteins and carrier proteins.
Are transport proteins specific? Cite an example that supports your response.
14. Peter Agre received the Nobel Prize in 2003 for the discovery of aquaporins.
What are they?
15. Consider the following materials that must cross the membrane. For each, tell how it is