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BIO301: Cell Biology

Unit 11: Specialized Organelle Functions   This unit will discuss the special functions of certain cell organelles. You might think of organelles as specialized organs that perform vital tasks such as digestion, detoxification, and energy production. Detoxification plays more of a role in a liver cell, whereas digestion is more important in a stomach cell, and energy production is more important in a muscle cell. Thus, although all cells have the same kinds of organelles, the relative abundance of each type is different based on the type of cell you are studying.

Unit 11 Time Advisory
Completing this unit will take you approximately 21 hours.

☐    Subunit 11.1: 3 hours

☐    Subunit 11.2: 2 hours

☐    Subunit 11.3: 3 hours

☐    Subunit 11.4: 3 hours

☐    Subunit 11.5: 5.5 hours

☐    Assessment: 4.5 hours

Unit11 Learning Outcomes
Upon completion of this unit, you will be able to - identify specialized organelles and their specific functions; - describe where one would expect to find more of specific organelles (demonstrating an understanding of organelle function as it relates to larger tissue- and organ-wide processes); and - describe the similarities and differences between mitochondria and chloroplasts.

11.1 Digestive Organelles   11.1.1 Lysosomes   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Lysosomes” and “Protein Degradation” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Lysosomes and Protein Degradation (both HTML)
 
Instructions: Read “Lysomes” and, in “Protein Degradation,” read the subsection entitled “Lysosomal Proteolysis.”

 Reading this text and taking notes should take approximately 2
hours.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.1.2 Peroxisomes   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Peroxisomes” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Peroxisomes (HTML)
 
Instructions: Read the introduction and the subsection “Functions of Peroxisomes,” along with all associated figures (Figs. 10.24–10.28). This will cover the topics outlined in 11.1.2 and 11.1.3.

 Reading this text and taking notes should take approximately 1
hour.  
    
 Terms of Use: Please respect the copyright and terms of use
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11.1.3 Glyoxysomes   This subunit is covered by the reading assigned beneath subunit 11.1.2. Focus on the subsection “Functions of Peroxisomes” and associated figures (Figs. 10.27–10.28).

11.2 Golgi   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “The Golgi Apparatus” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: The Golgi Apparatus (HTML)
 
Instructions: Read this section, along with all associated figures (Figs. 9.23– 9.28). This will cover the concepts covered in subunits 11.2.1–11.2.5.

 Reading this text and taking notes should take approximately 2
hours.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.2.1 cis-Golgi   This subunit is covered by the reading assigned beneath subunit 11.2. Focus on the “Organization of the Golgi” section and figure 9.23.

11.2.2 trans-Golgi   This subunit is covered by the reading assigned beneath subunit 11.2. Focus on the subsection “Organization of the Golgi” and figure 9.23.

11.2.3 Glycosylation   This subunit is covered by the reading assigned beneath subunit 11.2. Focus on the “Protein Glycosylation within the Golgi” section.

11.2.4 Transport of Membrane Proteins   This subunit is covered by the reading assigned beneath subunit 11.2. Focus on the subsection “Protein Sorting and Export from the Golgi Apparatus” and associated figure (Fig. 9.27).

11.2.5 Secretory Vesicles   This subunit is covered by the reading assigned beneath subunit 11.2.Focus on the “Protein Sorting and Export from the Golgi Apparatus” section.

11.3 Smooth ER   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “The Endoplasmic Reticulum” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: The Endoplasmic Reticulum (HTML)
 
Instructions: Read the subsection “The Smooth ER and Lipid Synthesis,” along with all associated figures (Figs. 9.17–9.19). This reading will also cover the topic outlined in subunit 11.3.1.

 Reading this text and taking notes should take approximately 2
hours.  
    
 Terms of Use: Please respect the copyright and terms of use
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11.3.1 Steroid Metabolism   This subunit is covered by the reading beneath subunit 11.3. Focus on the subsection “The Smooth ER and Lipid Synthesis” and associated figures (Figs. 9.17-9.18)

11.3.2 Carbohydrate Metabolism and the Smooth Endoplasmic Reticulum   One of the common functions of the smooth endoplasmic reticulum, particularly in liver hepatocytes, kidney cells, and intestinal cells, is the enzymatic breakdown of glycogen to form glucose. A major role of these organs is to maintain blood glucose homeostasis. When needed by the body, glycogen is broken down into individual glucose molecules. The glucose is converted to glucose-1-phosophate and then glucose-6-phosphate. Since cell membranes are typically impermeable to phosphorylated sugars, the glucose-6-phosphate must be converted to glucose so that it can leave the cell and enter the bloodstream for distribution throughout the body. Glucose-6-phosphatase, an enzyme bound to the smooth endoplasmic reticulum membrane, removes the phosphate group from glucose-6-phosphate; the glucose is then transported out of the cell by a transport molecule within the cell membrane.

11.3.3 Detoxification and Cytochrome P450 Family   - Reading: Wikibooks: Saylor.org’s “Cell Biology/Detoxification and Cytochrome P450 Family” Link : Wikibooks: Saylor.org’s Cell Biology/Detoxification and Cytochrome P450 Family” (HTML)

 Instructions: Read this section, along with associated figure
11.20.  

 Reading this text and taking notes should take approximately
1 hour.  
    
 Terms of Use: The article above is released under a [Creative
Commons Attribution-Share-Alike License
3.0](http://creativecommons.org/licenses/by-sa/3.0/). You can find
the original Wikibooks version of this article
[here](http://en.wikibooks.org/wiki/Structural_Biochemistry/Chemical_Bonding).

11.4 Mitochondria   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Mitochondria” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Mitochondria (HTML)
 
Instructions: Read the introduction and the subsection “Organization and Function of the Mitochondria,” along with all associated figures (Figs. 10.1 and 10.2). This reading will cover the topics outlined in subunits 11.4.1–11.4.5.

 Reading this text and taking notes should take approximately 2
hours.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.4.1 Outer and Inner Membranes   This subunit is covered by the reading and assigned beneath subunit 11.4. Focus on the subsection “Organization and Function of Mitochondria” and associated figure (Fig. 10.1).

11.4.2 Matrix   This subunit is covered by the reading and assigned beneath subunit 11.4. Focus on the subsection “Organization and Function of Mitochondria” and associated figure (Fig. 10.1).

11.4.3 Cristae  

This subunit is covered by the reading and assigned beneath subunit 11.4. Focus on the subsection “Organization and Function of Mitochondria” and associated figure (Fig. 10.1).

11.4.4 TCA Cycle and ATP Production   This subunit is covered by the reading and assigned beneath subunit 11.4. Focus on the subsection “Organization and Function of Mitochondria” and associated figure (Fig. 10.2).

11.4.5 Thermogenesis   - Reading: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: Professor Harvey Lodish et al.’s Molecular Cell Biology, 4e: “Electron Transport and Oxidative Phosphorylation” Link: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: Professor Harvey Lodish et al.’s Molecular Cell Biology, 4e: Electron Transport and Oxidative Phosphorylation (HTML)
 
Instructions: Read the subsection “Brown-Fat Mitochondria Contain an Uncoupler of Oxidative Phosphorylation.”

 Reading this text and taking notes should take approximately 1
hour.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.5 Chloroplasts   - Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Chloroplasts and Other Plastids” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Chloroplasts and Other Plastids (HTML)
 
Instructions: Read the introduction and the subsection “The Structure and Function of Chloroplasts,” along with all associated figures (Figs. 10.13–10.14). This reading will cover concepts outlined in subunits 11.5.1–11.5.6.

 Reading this text and taking notes should take approximately 2
hours.  
    
 Terms of Use: Please respect the copyright and terms of use
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11.5.1 Outer and Inner Membranes   This subunit is covered by the reading and assigned beneath subunit 11.5. Focus on figure 10.13.

11.5.2 Thylakoids   This subunit is covered by the reading and assigned beneath subunit 11.5. Focus on figure 10.13.

11.5.3 Photosynthetic Electron Transfer   This subunit is covered by the reading and assigned beneath subunit 11.5. Focus on figure 10.14.

11.5.4 Carbon-Fixation   - Reading: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: H. Lodish, A. Berk, S.L. Zipursky, et al.’s Molecular Cell Biology, 4e: “Section 16.3: Photosynthetic Stages and Light-Absorbing Pigments” Link: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: H. Lodish, A. Berk, S.L. Zipursky, et al.’s Molecular Cell Biology, 4e: Section 16.3: Photosynthetic Stages and Light-Absorbing Pigments (HTML)
 
Instructions: Scroll down to and read the section titled “Three of the Four Stages in Photosynthesis Occur Only during Illumination.”

 Reading this text and taking notes should take approximately 1
hour.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.5.5 Photosystem I and II   - Reading: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: H. Lodish, A. Berk, S.L. Zipursky, et al.’s Molecular Cell Biology, 4e: “Section 16.4: Molecular Analysis of Photosystems” Link: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: H. Lodish, A. Berk, S.L. Zipursky, et al.’s Molecular Cell Biology, 4e: Section 16.4: Molecular Analysis of Photosystems (HTML)
 
Instructions: Scroll down to the section titled “Chloroplasts Contain Two Functionally and Spatially Distinct Photosystems.” Begin reading here and continue until the end of the webpage.

 Reading this text and taking notes should take approximately 1
hour.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

11.5.6 Similarities to Mitochondria   This subunit is covered by the reading assigned beneath subunit 11.5. There are many similarities between chloroplasts and mitochondria. Both have dual-layer membranes, inner compartment folding, and proton-driven ATP synthases. There are also differences, however, between their carbon-fixation reactions and, of course, respective degrees of light-dependency.

  • Assessment: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Questions – Mitochondria, Chloroplasts, Peroxisomes” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Questions – Mitochondria, Chloroplasts, Peroxisomes (HTML)

    Instructions: Answer questions 1 and 3–6. Please note that answers are directly below the questions asked; try to cover them while you answer the questions yourself.

    Completing this assessment should take approximately 1 hour and 30 minutes.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Assessment: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: “Questions – The Endoplasmic Reticulum, Golgi Apparatus, and Lysosomes” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates, Inc.: Professor Geoffrey Cooper’s The Cell: A Molecular Approach, 2e: Questions – The Endoplasmic Reticulum, Golgi Apparatus, and Lysosomes (HTML)

    Instructions: Answer questions 1–5. Please note that answers are posted directly below the questions asked; try to cover them while you answer the questions yourself.

    Completing this assessment should take approximately 1 hour and 30 minutes.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Assessment: The Saylor Foundation’s “Unit 11 Quiz” Link: The Saylor Foundation’s Unit 11 Quiz” (HTML)
     
    Instructions: Please complete the linked quiz to test your knowledge of the material covered in Unit 11.

    Completing this assessment should take approximately 3 hours.