MCB 229 Spring 2000 Study Guide 6 Prof. Terry
Covers Lecture for Feb. 17

This study guide is intended for you to use while you are doing the assigned text reading. Quiz questions will be made with reference to topics in this study guide. Quiz #6, based on questions from this study guide, must be completed by midnight before the class on Thursday, Feb. 17. You will need to create your "myWebCT" account and visit the MCB 229 WebCT page in order to access this quiz.

Chapter 9 (p. 164-168; 174-176); also refer to Appendix II, p. A13-15 and A17-19.
  1. What is the difference between the following terms: metabolism, anabolism, catabolism?
  2. "Lehninger's overview of metabolism", described on p. 164 and in Fig. 9.1, is a very good summary. Read this a couple of times to fix the view of the "forest" in mind. Once we get into the "trees" (metabolic pathways), it's easy to forget how everything ties together.
  3. What is an amphibolic pathway?
  4. You should remember the structure of glucose from previous biology or chemistry courses. If you feel any need of a "refresher", look at pp. A5-A7 in your text. Be able to recognize glucose from its linear and ring representations (Fig. AI.9).
  5. Glucose is the most abundant sugar on this planet. Plants store enormous amounts of organic Carbon in forms such as cellulose, starch, lignin, and other polysaccharides, all derived ultimately from glucose. The breakdown of glucose is arguably the most indispensable feature in metabolism, and almost all organisms have enzymes for this purpose. What are the 3 pathways (enzyme sets) available for glycolysis? For each pathway, be able to recognize major points in which they differ.
  6. Where are enzymes of the glycolytic pathway located? How many enzymes are required (count the number of chemical reactions: each reaction must have an enzyme if the pathway is to happen faster than molasses dripping)?
  7. How many oxidation reactions occur during glycolysis? What happens to the electrons in these oxidation reactions?
  8. Starting with one glucose molecule, what are the products of glycolysis? How much ATP is produced? (Hint: note that ATP is initially spent, and later synthesized. Calculate the net gain of ATP per glucose.)
  9. The pentose phosphate pathway can be used for both anabolic and catabolic purposes. If this pathway is used strictly for catabolism, what products are produced from the complete breakdown of one glucose molecule?
  10. How many oxidation reactions occur during the pentose phosphate pathway? What happens to the electrons in these oxidation reactions? How does this differ from the results of glycolysis?
  11. Is CO2 released during the pentose phosphate pathway? If so, where? How many C-atoms do the resulting molecules have? Which important cell polymer requires these product molecules as an important part of its structure?
  12. In which organisms is the Entner-Doudoroff pathway found? Is it found principally in gram-negative or gram-positive bacteria? What are the products of one molecule of glucose in this pathway? How much ATP is produced? How does this differ from glycolysis?
  13. What is fermentation? What happens to electrons in NADH during fermentation reactions? How is this of value to the cell?
  14. Fermentations are named after the type(s) of products formed. Identify at least 5 types of fermentation products (study Fig. 9.14 carefully).
  15. How do homolactic and heterolactic fermenters differ?