Name
Date
Basic Concepts
Master
6
Class
Plasma Membrane
Polar
head
Use with Chapter 7, Section 7.2
Phosphate
group
Glycerol
backbone
Fatty
acids
Phospholipid
molecule
Cholesterol
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Membrane
protein
Membrane
protein
Cytoplasm
Filaments of cytoskeleton
BASIC CONCEPTS
TRANSPARENCY MASTER 6 BIOLOGY: The Dynamics of Life
13
Name
Date
Class
Basic Concepts
Worksheet
6
Plasma Membrane
Use with Chapter 7, Section 7.2
1. Describe the phospholipid in the upper left part of the transparency.
2. Which end of a phospholipid is attracted to water?
3. How are phospholipids oriented in the plasma membrane?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. What is the function of membrane proteins?
5. Why is the model of a membrane shown in the transparency referred to as the
fluid mosaic model?
6. How would the membrane shown in the transparency behave if its fatty acid tails
consisted mostly of unsaturated fatty acids?
7. What is the function of the cholesterol molecules shown in the transparency?
14
TRANSPARENCY WORKSHEET 6 BIOLOGY: The Dynamics of Life
BASIC CONCEPTS
Teacher Guide
6
■ Plasma Membrane
Use with Chapter 7, Section 7.2
Purpose
Answers to Student Worksheet
• To show the bilayer structure of the plasma
membrane
1. The phospholipid in the transparency is a
Teaching Suggestions
2.
• Demonstrate the formation of a thin lipid layer
by placing a drop of baby oil on the surface of a
beaker of water.
3.
• Discuss the fluid mosaic model as an operational
definition of the plasma membrane.
• Point out that the degree of fluidity of the plasma
membrane is related to the proportion of saturated
and unsaturated fatty acids it contains. Relate the
property of fluidity to the freezing temperatures
of saturated and unsaturated fatty acids.
4.
5.
Extension: Laboratory
• Make a culture of Paramecium. Place some yeast
6.
7.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
that have been colored with Congo red in the
culture for half an hour. Have students observe
the membranes that form around the colored
yeast particles inside the paramecia.
molecule consisting of a phosphate group
and two fatty acid chains linked to glycerol.
The phosphate, or polar end, is attracted to
water.
There are two layers of phospholipids in the
plasma membrane, arranged with the phosphate
ends facing the outside of each layer and the
fatty acid ends facing the inside.
Many proteins regulate the permeability of the
membrane to various substances, some function
as enzymes, and others serve as markers that
enable the immune system to distinguish an
organism’s own cells from foreign cells.
The model shows phospholipid molecules that
are not chemically bonded to one another but,
rather, are free to move sideways through their
layer, allowing the membrane to behave like a
fluid.
It would be very fluid.
The cholesterol molecules help stabilize the
phospholipids.
BASIC CONCEPTS TEACHER GUIDE
BIOLOGY: The Dynamics of Life
169