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CHEM203: Bioinorganic Chemistry

Unit 7: The Enzymes And Proteins Used For Oxygen Processing   Once oxygen is transported and transferred to the desired site, it needs to be incorporated into bio-organic molecules.  This process occurs via several chemical reactions, such as hydroxylations and oxygenations.  Different enzymes catalyze these reactions, but they all use metal ions in their activation centers.  In this unit, you will learn about the structures and functions of the metals involved in these processes.

Unit 7 Time Advisory
This unit should take you approximately 7.25 hours to complete.
 
☐    Subunit 7.1: 6.5 hours      

☐    Subunit 7.2: 0.5 hour

☐    Subunit 7.3: 0.25 hour

Unit7 Learning Outcomes
Upon successful completion of this unit, the student should be able to:
- Describe how oxygen, once it has been transported by bioinorganic molecules, is incorporated into bio-organic molecules. - Identify the key metal-ion-containing enzymes that catalyze these processes. - Discuss oxygen toxicity and antioxidant enzyme activity.

7.1 Superoxide Dismutase (SOD)   - Reading: Bioinorganic Chemistry: Dr. Joan Selverstone Valentine’s “Chapter 5: Dioxygen Reactions” Link: Bioinorganic Chemistry: Dr. Joan Selverstone Valentine’s “Chapter 5: Dioxygen Reactions” (PDF)
 
Instructions: Please click on the link above to access the online textbook.  Then, scroll down the webpage and click on the link for chapter 5 to open a PDF version of the chapter, which you should read in its entirety.  You may also choose to download a PDF of the entire book at the top of the webpage, and then navigate to chapter 5, which begins on page 253.
 
In this reading you will discover that oxygen, essential for aerobic life, also can cause dioxygen toxicity in high concentrations.  Superoxide dismutase, catalases, and peroxidases work together to remove excess dioxygen as well as the unwanted side products of dioxygen reactions.  For this subunit, focus in particular on superoxide dismutase, or SOD, specifically covered in section VII of the textbook, on pages 298-310.
 
Please note that this reading also covers material you need to know for subunits 7.2-7.3, found below.  When you reach those subunits, you may find it helpful to refer back to this reading to review specific topics.
 
This reading, including note-taking, should take you approximately 6 hours to complete.

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.
  • Reading: Wikipedia’s “Superoxide Dismutase” Link: Wikipedia’s “Superoxide Dismutase” (PDF)

    Instructions: Please click on the link above to access and read the entire Wikipedia entry on superoxide dismutase.  This material gives you a relatively concise description of superoxide dismutase, or SOD, which can be Zn/Fe- based, Fe/Mn-based, or Ni-based, depending on the biological species in which it is present.  This topic is covered in more detail in Bioinorganic Chemistry, the online textbook featured in this course.  If you find yourself struggling with understanding any of the material presented in this reading, you may find it helpful to refer back to page 191 from chapter 4 of the textbook, as well as pages 263, 265-266, and 298-305 from chapter 5.
           
    This reading should take you approximately 30 minutes to complete.
     
    Terms of Use: The article above is released under a Creative Commons Attribution-Share-Alike License 3.0. You can find the original Wikipedia version of this article here.

7.2 Catalase   - Reading: Wikipedia’s “Catalase” Link: Wikipedia’s “Catalase” (PDF)

 Instructions: Please click on the link above to access and read the
entire Wikipedia entry, which gives you a relatively concise
description of catalase.  Catalase is the iron-based enzyme
responsible for the breakdown of hydrogen peroxide, a harmful
byproduct of several metabolic processes.  This topic is covered in
more detail in [*Bioinorganic
Chemistry*](http://authors.library.caltech.edu/25052/), the online
textbook featured in this course.  If you find yourself struggling
with understanding any of the material presented in this reading,
you may find it helpful to refer back to page 191 from chapter 4 of
the textbook, as well as pages 263 and 295-298 from chapter 5.  
    
 This reading should take you approximately 30 minutes to
complete.  
    
 Terms of Use: The article above is released under a [Creative
Commons
Attribution-Share-Alike](http://creativecommons.org/licenses/by-nc-sa/3.0/)[ License
3.0](http://creativecommons.org/licenses/by-nc-sa/3.0/). You can
find the original Wikipedia version of this article
[here](http://en.wikipedia.org/wiki/Catalase).

7.3 Peroxidase   - Reading: Wikipedia’s “Peroxidase” Link: Wikipedia’s “Peroxidase” (PDF)

 Instructions: Please click on the link above to access and read the
entire webpage.  This material gives you a general description of
peroxidase.  Peroxidase is similar to catalase, since both are
iron-based enzymes that break down hydrogen peroxide; however,
peroxidases have a much more general substrate and can break down
other types of biological peroxides as well.  This topic is covered
in more detail in [*Bioinorganic
Chemistry*](http://authors.library.caltech.edu/25052/), the online
textbook featured in this course.  If you find yourself struggling
with understanding any of the material in this reading, you may find
it helpful to refer back to pages 263 and 295-298 from chapter 5 of
the textbook.  
          
 This reading should take you approximately 15 minutes to
complete.  
    
 Terms of Use: The article above is released under a [Creative
Commons
Attribution-Share-Alike](http://creativecommons.org/licenses/by-nc-sa/3.0/)[ License
3.0](http://creativecommons.org/licenses/by-nc-sa/3.0/). You can
find the original Wikipedia version of this article
[here](http://en.wikipedia.org/wiki/Peroxidase).