NAME__________________________________________DATE_______________
Chapter 7 Key Concepts
IDEA 2 and SB1
Membrane Structure and Function
Guided Reading
Define: selective permeability, amphipathic, and fluid mosaic model
Concept 7.1: Cellular membranes are fluid mosaics of lipids and proteins
1. What is meant by membrane
fluidity? Describe the
movements seen in the
membrane.
2. What three factors can affect
membrane fluidity?
3. Explain how cholesterol affects
the fluidity of membranes at
different temperatures?
4. How have plants, such as winter
wheat, adapted to colder
temperatures?
5. Membrane function is
determined by different sets of
proteins. Define the two main
groups of membrane proteins.
a. Integral proteinsb. Peripheral proteins6. Complete the table using figure
7.9 regarding functions performed by membrane proteins.
Function of membrane proteins
Description
Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercellular joining
Attachment to the cytoskeleton
and ECM
7.
8.
9.
10.
11.
What role do carbohydrates play in the cell membrane?
Define glycolipids and glycoproteins.
What are some examples of why cell to cell recognition important?
Explain the importance of variation among carbohydrate chains within the cell membrane.
Summarize how the structure of the membrane is created by the ER and golgi apparatus.
Concept 7.2: Membrane structure results in selective permeability
12. Compare and contrast the permeability of the cell membrane in terms of polar molecules vs. nonpolar molecules.
13. Distinguish between channel proteins and carrier proteins.
14. Are transport proteins specific? Cite an example that supports your response (hint- aquaporins).
Concept 7.3: Passive transport is diffusion of a substance across a membrane with no energy investment
15. Vocabulary review – define the following terms in your own words
 Diffusion
 Facilitated diffusion
 Concentration gradient
 Passive transport
 Osmosis
 Tonicity
 Isotonic
 Hypertonic
 Hypotonic
 Solute
 Solvent
 Active transport
16. Briefly describe one important
example of diffusion.
17. Compare the balance of water in
cells with and without cell walls?
18. Explain how organisms without
cell walls have adapted to live in
hyper or hypotonic environments.
Concept 7.4: Active transport uses energy to move solutes against their gradients
19. Explain active transport in terms of how it
works and why it is important.
20. Explain how the sodium-potassium pump
works to transport ions across the cell
membrane against the concentration
gradient (use figure 7.16 to help).
21. Explain how proton pumps work.
22. How has knowledge of these concepts
helped dehydration issues as a result of
diarrhea in people living in developing
countries?
Concept 7.5: Bulk transport across the plasma
membrane occurs by exocytosis and endocytosis
23. Complete the following table to compare
exocytosis and endocytosis.
Endocytosis
Both Endo and Exocytosis
Exocytosis
Definition-
Definition-
Examples-
Examples-
24. Summarize the three kinds of endocytosis using the table below.
Type of Endocytosis
Explanation
Phagocytosis
Pinocytosis
Receptor-mediated
endocytosis
25. Explain what the term ligands mean and their role in in transporting cholesterol in humans.
Testing Your Knowledge -Self Quiz Answers
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2._____
3._____
4._____
5._____
Complete Question 6 below:
Answers for parts
b.
d.
e.
Write About It –
1. Cystic Fibrosis (CF) is the result of a mutated gene on chromosome seven and is inherited by offspring from their parents. CF is a
recessive trait resulting in cells that cannot regulate sodium, chloride and bicarbonate transport. Using your knowledge of active
transport and the sodium-potassium pump, explain where in the process you would expect the problem to occur in individuals with
CF.