PHY 580 - ASTROBIOLOGY FOR TEACHERS


ADDITIONAL QUESTIONS FROM THE READING


Chapter #5 Energy and Life in Unique environments on Earth.

 

1. What is the currency or medium of exchange for energy in all of terrestrial life? (page 72)

2. How is adenosine triphosphate used in chemical reactions as a source of energy? How or where is the energy "stored" in adenosine triphosphate? (page 73)

3. What is meant by the term oxidized? What happens to an oxidized atom or molecule? (page 74)

4. What is meant by the term reduced? What happens to an reduced atom or molecule? (page 74)

5. What is meant by the term redox-reaction. (page 74)

6. Provide a brief description of the fundamental characteristics for each of the three chemical pathways of life &endash; photosynthesis, oxidation, and fermentation. (page 75 &endash; 77)

7. Is CO2 gas an organic or inorganic carbon source? Would life forms utilizing CO2 as a carbon source be considered autotrophic or heterotrophic? (page 75)

8. Consider the simplified chemical reaction (4) shown on page 76 to illustrate the photosynthesis process. Using the prefix table shown in figure 5.3, give the full label (including labels for both the carbon source and energy source) for a life form using this biochemical pathway. (page 76)

9. Consider the simplified chemical reaction (5) shown on page 77 to illustrate the oxidation process. Using the prefix table shown in figure 5.3, give the full label (including labels for both the carbon source and energy source) for a life form using this biochemical pathway. (page 77)

10. Consider the simplified chemical reaction (6) shown on page 77 to illustrate the fermentation process. Using the prefix table shown in figure 5.3, give the full label (including labels for both the carbon source and energy source) for a life form using this biochemical pathway. (page 77)

11. Consider the simplified chemical reaction (7) shown on page 78 to illustrate a unique oxidation process. Using the prefix table shown in figure 5.3, give the full label (including labels for both the carbon source and energy source) for a life form using this biochemical pathway. (page 78)

12. Explain why the oxidation process depicted in the chemical reaction (5) on page 77 would be more efficient (produce a greater amount of energy) than the fermentation process depicted in the chemical reaction (6) shown on page 77. (page 77)

13. Why may the bacteria capable of oxidizing iron have been important early in the Earth's history. Under what conditions to iron oxidizing bacteria thrive? (page 78)

14. There are bacteria that thrive at depth greater than 1 km beneath the surface of the Columbia River Basalts. Since no sunlight is available at these depths, what do these bacteria use as an energy source? How is this done?(page 78)

15. At what temperature is the most extreme hyperthermophile known to have thrived in the lab? (page 79)

16. What are the most common locations on Earth to find hyperthermophiles? (page 79)

17. Explain what produces the "bulls-eye" patterns around hot springs in Yellowstone National Park? (page 83)

18. Explain how lithoautotrophs are able to thrive in the harsh Antarctic desert valleys? (page 83- 84)

19. What appears to be the one environmental characteristic that is common to all locations on Earth where life exists? How does it appear that this characteristic aids living systems? (page 84)

20. What are the elements that compose the molecules that form the backbone of the double helix of DNA? (page 85)

21. What are the names given to the four bases of DNA? (page 86)

22. What feature of the DNA double helix actually contains the genetic information? (page 86)

23. Describe how it is possible to exactly reproduce a DNA molecule from only have of the double helix. (page 87)

24. Does RNA also have a double helix structure? (page 87)

25. Describe how DNA, mRNA and tRNA are utilized within a cell to produce required proteins. (page 87)

26. Briefly describe how the examining the rRNA of different species can be used to track the how these species diverged from a common ancestor. (page 88 - 89)

27. Does the "Tree of Life" illustrate a timeline for life on Earth? If so how does it work? If not, what does it represent? (page 89)

28. What are the names given to the three branches or "domains" in the "Tree of Life" shown if Figure 5.12 on page 90? (page 89 &endash; 90)

29. What fundamental difference exists between the domain archaea and the bacteria?

30. What is the significance, to the history of life on Earth, that hyperthermophiles are the life forms that appear to be located closest to the "root" of the tree of life? (page 91)


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