Download 1.3 study guide - Peoria Public Schools

Topic 1.3: Membrane Structures
Key facts
 Cell membranes include phospholipids and proteins. These proteins may be classified as integral or
peripheral proteins.
 It is the hydrophobic and hydrophilic properties of phospholipids that maintain the structure of cell
membranes.
 Functions of membrane proteins include hormone binding sites, enzyme activity, cell adhesion, cell-tocell communication, channels for passive transport, and pumps for active transport.
 The term plasma membrane, not cell surface membrane, should be used for the membrane surrounding
the cytoplasm.
 Phospholipids form bilayers in water due to the amphipathic properties of phospholipid molecules.
 Membrane proteins are diverse in terms of structure, position in the membrane and function.
 Cholesterol is a component of animal cell membranes.
Skill

Analysis of evidence from electron microscopy that led to the proposal of the Davson-Danielli model.

Analysis of the falsification of the Davson-Danielli model that led to the singer-Nicolson model.
Complete the following.
1. Draw and label a diagram to show the structure of membranes. The diagram should show the phospholipid
bilayer, cholesterol glycoproteins, and integral and peripheral proteins.
2. Describe the major characteristics of the nuclear membrane.
3. What are the major components of a phospholipid which occurs in cellular membranes?
4. Animal cell membranes contain cholesterol to maintain proper membrane fluidity. Since plant cell
membranes do not contain cholesterol, how do they maintain membrane fluidity?
5. Differentiate between a peripheral and an integral protein when examining a cell membrane.
6. Which end of a phospholipid is hydrophobic?_____________________Which is
hydrophilic?____________________
7. Explain why different cell types vary in the amount of membrane proteins.
8. What general type of membrane proteins would make up channel proteins?
9. Name 6 general function of cell membrane proteins.
10. Explain what membrane glycoproteins are.
11. Discuss the use of cholesterol in cell membranes.