Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
Chapter 6: A Tour of the Cell
1. A major difference between prokaryotic and eukaryotic cells is the location of their DNA.
Describe this difference.
2. On the sketch of a prokaryotic cell, label each of these features and give its function or
description.
- cell wall
- plasma membrane
- bacterial chromosome
- nucleoid
- cytoplasm
- flagella
3. Why are cells so small? Explain the relationship of surface area to volume.
4. Found within the nucleus are the chromosomes. They are made of chromatin. What are the
two components of chromatin? When do the thin chromatin fibers condense to become
distinct chromosomes?
5. When are the nucleoli visible? What molecule is assembled here?
6. What is the function of ribosomes? What are their two components?
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Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
7. Ribosomes in any type of organism are all the same, but we distinguish between two types of
ribosomes based on where they are found and the destination of the protein product made.
Complete this chart to demonstrate this concept.
8. The endoplasmic reticulum (ER) makes up more than half the total membrane system in
many eukaryotic cells. Use this sketch to explain the lumen, transport vesicles, and the
difference between smooth and rough ER.
9. List and describe three major functions of the smooth ER.
10. The rough ER is studded with ribosomes. As proteins are synthesized, they are threaded into
the lumen of the rough ER. Some of these proteins have carbohydrates attached to them in
the ER to form glycoproteins. What does the ER then do with these secretory proteins?
11. The transport vesicles formed from the rough ER fuse with the Golgi apparatus. Describe
what happens to a transport vesicle and its contents when it arrives at the Golgi.
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Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
12. What is a lysosome? What do they contain? What is their pH and why is this pH logical in
the context of this organelle’s function?
13. What happens in Tay-Sachs disease? Explain the role of the lysosomes in Tay-Sachs.
14. There are many types of vacuoles. Briefly describe the function of:
- food vacuoles
-
contractile vacuoles
-
central vacuoles in plants
15. Use this figure to explain how the elements of the endomembrane system function together to
secrete a protein and to digest a cellular component. Label as you explain.
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Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
Chapter 7: Membrane Structure and Function
16. Explain what is meant when we say a molecule is amphipathic.
17. What is the fluid mosaic model of membrane structure? Describe this model.
18. What is meant by membrane fluidity? Describe the movements seen in the fluid membrane.
19. Describe how each of the following can affect membrane fluidity:
- decreasing temperature
-
phospholipids with unsaturated hydrocarbon chains
-
cholesterol
20. Membrane proteins are the mosaic part of the model. Describe each of the two main
categories:
- integral proteins
-
peripheral proteins
21. Membrane carbohydrates are important in cell-cell recognition. What are two examples of
this?
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Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
22. Distinguish between channel proteins and carrier proteins.
23. Are transport proteins specific? Cite an example that supports your response.
24. Peter Agre received the Nobel Prize in 2003 for the discovery of aquaporins. What are they?
25. Consider the following materials that must cross the membrane. For each, tell how it is
accomplished.
26. What is facilitated diffusion? Is it active or passive? Cite two examples.
27. Label the hypotonic solution, isotonic solution,
and hypertonic solution. What is indicated by the
blue arrows? Label them. Which cell is lysed?
Turgid? Flaccid? Plasmolyzed? Apply all these
labels.
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Unit 2 Reading Guide: Holtzclaw and Holtzclaw by M. Chirby
28. Describe active transport. What type of transport proteins are involved, and what is the role
of ATP in the process?
29. On the diagram below, add these labels: facilitated diffusion with a carrier protein, facilitated
diffusion with a channel protein, active transport with a carrier protein, simple diffusion. For
each type of transport, give an example of a material that is moved in this manner.
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