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AP Biology
Mr. Wallis
Reading Guide: Campbell Chapter 7
Name:
due date:
Chapter 7: Membrane Structure and Function
7.1 CELLULAR MEMBRANES ARE FLUID MOSAICS OF LIPIDS AND PROTEINS
Notes:
 Selective permeability:

Amphipathic:

Fluid Mosaic Model:
Describe the fluid mosaic model; include a labeled sketch.
Membrane Models
Summarize the research method shown in figure 7.4 on page 127:
The Fluidity of Membranes
Explain what it means for phospholipids to freely move in a plane of a membrane, but not to “flip-flop”:
(Use figure 7.5)
Explain how cholesterol 1) stabilizes the membrane and 2) lowers the temperature at which the membrane will
solidify (Use figure 7.5)
Is this good or bad? Why?
page 1 of 7
Membrane Proteins and Their Functions
Notes:
 Mosaic (from dictionary):

Integral proteins:

Peripheral proteins:
How is a membrane similar to a mosaic?
Using figure 7.9, explain the role of a protein in:
1) Transport:
2) Enzymatic activity:
3) Signal Transduction:
4) Intercellular Joining:
5) Cell-Cell recognition:
6) Attachment to the cytoskeleton and extracellular matrix:
The Role of Membrane Carbohydrates Cell-Cell Recognition
What is cell-cell recognition?
Why is it important?
What role do carbohydrates play in cell-cell recognition?
7.2 MEMBRANE STRUCTURE RESULTS IN MEMBRANE PERMEABILITY
What is selective permeability?
Why would a cell membrane need to be selectively permeable?
Chapter 7 Reading Guide
page 2 of 7
Permeability of the Lipid Bilayer
What types of molecules can cross a membrane, what cannot? Give examples.
Transport Proteins
What is a transport protein?
Explain the two different ways in which a transport protein can transport a molecule across a membrane
1.
2.
7.3 PASSIVE TRANSPORT IS DIFFUSION OF A SUBSTANCE ACROSS A MEMBRANE WITH NO ENERGY INVESTMENT
Notes:
 Diffusion:

Concentration gradient:

Passive transport:
What determines the direction of traffic across a membrane?
What actually drives molecules across membranes?
Effects of Osmosis on Water Balance
Notes:
 Hypertonic:

Hypotonic:

Isotonic:

Osmosis:
How does osmosis work? (Reference figure 7.12)
Chapter 7 Reading Guide
page 3 of 7
Water Balance of Cells without Walls
Notes:
What types of cells do NOT have cell walls?
What happens to a cell placed in a hypertonic environment? (Reference figure 7.13)
What happens to a cell placed in a hypotonic environment?
What happens to a cell placed in a isotonic environment?
Explain how an animal cell maintains water balance.
Sketch figure 7.13 and summarize what happens to animal cells and plant cells placed in different environments
Water Balance of Cells with Walls
Notes:
 Turgid:

Flaccid:

Plasmolysis:
Chapter 7 Reading Guide
page 4 of 7
Facilitated Diffusion: Passive Transport Aided by Proteins
Define:
 Facilitated diffusion:

Gated channels:
What is the function of transport proteins?
7.4 ACTIVE TRANSPORT USES ENERGY TO MOVE SOLUTES AGAINST THEIR GRADIENTS
Notes:
 Active transport:

Sodium-potassium pump:
Sketch figure 7.16 and explain active transport in the Na-K pump:
Summarize passive transport, facilitated diffusion, and active transport. (see figure 7.17)
What is the role of ATP in active transport?
What is ATP’s role in passive transport? (tricky, tricky!!!)
Chapter 7 Reading Guide
page 5 of 7
How Ion Pumps Maintain Membrane Potential
Notes:
 Membrane potential:

Electrochemical gradient:

Electrogenic pump:

Proton pump:
Explain how can a voltage be generated across a membrane:
Sketch figure 8.18 and summarize how a proton pump works.
Cotransport:: Coupled Transport By a Membrane Protein
Sketch figure 7.19 and explain how cotransport can “couple” the transport of one solute to another.
7.5 BULK TRANSPORT ACROSS THE PLASMA MEMBRANE OCCURS BY EXOCYTOSIS AND ENDOCYTOSIS
Notes:
 Exocytosis:

Endocytosis:

Phagocytosis:

Pinocytosis:
Chapter 7 Reading Guide
page 6 of 7

Receptor-mediated exocytosis:

Ligands:
Why are exocytosis and endocytosis important to a cell?
Use figure 7.20 (p. 139) to explain the three types of endocytosis. (show the ligand in receptor-mediated!)
Questions / Additional Lecture Notes:
Chapter 7 Reading Guide
page 7 of 7