7. The pentose phosphate pathway produces: a. CO2 b. Glyceraldehyde-3-phosphate c. NADPH d. All of the above e. A & C

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1 SI Practice Exam Three Please remember I do not write these questions myself, and use resources and practice tests provided to me by your professor and they are also approved by the professor prior to dispersal. :) 1. Which of the following is correct about the Embden-Meyerhoff pathway? a. NAD+, the reduced form of the coenzyme, causes the oxidation of glyceraldehyde-3-phosphate b. NADH, the reduced from of the coenzyme, causes the reduction of glyceraldehyde-3-phosphate c. Part of the energy provided by the reduction of glyceraldehyde-3-phosphate is used to make a high energy bond d. NAD+, the oxidized form of the coenzyme, causes the oxidation of glyceraldehyde-3-phosphate e. NADH, the oxidized form of the coenzyme, causes the reduction of glyceraldehyde-3-phosphate 2. Which of the following is incorrect about chemoorganotrophs? a. They are all heterotrophs. b. They include humans and animals. c. They do not compete with chemolithotrophs. d. They receive energy from organic chemicals. e. They do not use fermentation for energy. 3. Fermentation: a. Produces 2 net ATP b. May produce lactate c. Both SLP and oxidative phosphorylation are used to make ATP d. All of the above e. A & B 4. In the electron transfer chain: a. The redox potential plays no role in determining the amount of energy produced during electron transfer. b. The redox potential of pairs at the beginning of the chain are more negative than those at the end of the chain. c. The transfer of electrons through the chain produces a high concentration of protons inside the cell. d. All carriers present are electron carriers only. e. Both B & D 5. Which of the following is correct? a. A negative free energy change is considered nonspontaneous. b. A negative free energy change for a reaction determines that it will go fast towards the formation of the reactant. c. Free energy calculations determine the velocity of the reaction. d. Activation energy determines the equilibrium concentration of reactants and products. e. None of the above. 6. Which of the following statements is true? a. More negative values are found at the bottom of the redox tower; they catch dropping electrons. b. Metabolic pathways are either catabolic or anabolic, but not both. c. Some aerobic bacteria lack the EM or ED pathways, so they will use the pentose phosphate pathway for glycolysis. d. Acetyl-CoA has a high energy thioester bond. 7. The pentose phosphate pathway produces: a. CO2 b. Glyceraldehyde-3-phosphate c. NADPH d. All of the above e. A & C

2 8. The Krebs cycle generates all of the following from one acetyl-coa oxidized, except: a. 3 NADH molecules b. 2 ATP molecules c. 1 FADH2 molecule d. 2 CO2 molecules e. All of these are Krebs cycle products. 9. The enzymes for the TCA cycle are found in what part of eukaryotic cells? a. Cytoplasm b. Inner membrane of the mitochondria c. Mitochondrial matrix d. Outer membrane of the mitochondria 10. Which are the major functions of the TCA cycle? a. Production of energy b. Creation of precursor metabolites for biosynthesis c. Electron transport carrier production d. A & B 11. Which of the following statements is true? a. Bacterial electron transport chains have a higher P/O ratio than eukaryotic electron transport chains. b. The electron transport chain system between eukaryotes and prokaryotes uses the same cytochromes. c. ATP fuels the rotation of the bacterial flagella. d. Proton flow is inward during ATP synthesis, regarding ATP synthase. 12. Which are possible electron acceptors for anaerobic respiration? a. Carbon dioxide b. Sulfate c. Methane d. All of the above e. A & B 13. A molecule that binds nonconvalently to an enzyme at the active site and prevents a substrate from binding to it and reaction is a/an inhibitor. a. Competitive b. Allosteric c. Noncompetitive d. A & B e. B & C 14. Which of the following types of cellular work involves synthesizing macromolecules or breaking down macromolecules? a. Transport Work b. Chemical Work c. Mechanical Work 15. Which is true about coenzymes? Select all that apply. a. Bind to enzymes by strong covalent bonds b. Can only shuttle electrons, never protons c. Help shuttle electrons from glycolysis to the ETC d. Are often vitamin derivatives e. Include NAD+/NADH and H+ 16. A delta G value is +50 kcal under standard conditions. Which of the following is true about this value? Select all that apply. a. The reaction is endergonic. b. The reaction requires an input of energy. c. The reaction is spontaneous.

3 d. The reaction undergoes a release of energy. Use the following information of the next two questions. The redox potential of a redox pair is (X/X- 1) and the other redox pair is (Y+1/Y) 17. What is the reducing agent? a. Y+1 b. X-1 c. Y & Y+1 d. X 18. What is the free energy change if the equivalents of e- equals to 2? a. 2(23)(-0.23) kcal b. -(2)(23)(-0.23) kcal c. (2)(23)(-0.47) kcal d. -(2)(23)(-0.47) kcal e. -(2)(23)(0.23) kcal 19. Of the following, which yields the highest energy upon hydrolysis of one of its energy yielding bonds? a. ADP -> AMP b. Glucose-6-phosphate c. ATP -> ADP d. Phosphoenolpyruvate e. Acetyl coa 20. Which is true about enzymes? Select all that apply. a. They increase the velocity of a reaction significantly by lowering the activation energy. b. When binding to substrates, the binding is more like a lock and key instead of induced fit. c. The enzyme speeds up the velocity of a reaction and changes the equilibrium concentrations of the reactants and products. d. They have an active binding site for the substrate and a different binding site for the coenzyme. 21. Select all that apply about the heme group found in cytochrome c. a. It binds loosely to the cytochrome c. b. It is a coenzyme. c. It is a prosthetic group. d. It contains a redox site with Fe+3/Fe+2. e. It shuttles both electrons and protons. 22. Which term is the measure of randomness or disorder in a system? a. Enthalpy b. Entropy c. Free energy d. Synergy 23. Which law of thermodynamics states that physical and chemical processes occur in such a way that disorder increases in a system? a. First b. Second c. Third d. Fourth 24. Which of the following statements is true? Select all that apply. a. The EM pathway is most commonly used for soil bacteria and gram-negative bacteria. b. ATP has two high energy bonds. c. Endergonic reactions can not be made to move forward under any circumstance. d. The reductant is the electron acceptor in a redox reaction. e. NADP+ is used as an electron carrier by organisms.

4 25. Which of the following electron transport molecules transfers electrons ONLY? a. Ubiquinone b. NADP c. FAD d. Ferredoxin 26. The loosely attached nonprotein component of an enzyme is called the: a. Apoenzyme b. Coenzyme c. Holoenzyme d. Allosteric enzyme 27. Select all of the statements that are correct. a. Enzymes alter equilibrium constants and the rate of a reaction. b. With the amount of enzyme constant, the rate of a reaction will increase as the substrate concentration increases. c. Enzymes are named based on the substrates they act on and the type of reactions they catalyze. d. A holoenzyme is the protein component and nonprotein component. e. If products are being formed at a rapid speed, the reaction is proceeding at terminal velocity. 28. Sulfanilamide is a drug that interferes with bacterial enzymes in which of the following ways? a. Feedback Inhibition b. End-product inhibition c. Allosteric inhibition d. Competitive inhibition e. A & B 29. All of the following are associated with the process of Embden-Meyerhof except: a. Phosphorylation of glucose b. Substrate-level phosphorylation c. Production of pyruvic acid d. Production of NADPH 30. Which of the following is incorrectly paired? a. Krebs Cycle: three molecules of NADH per one molecule of acetyl-coa b. ETC: three molecules of ATP per molecule of NADH c. Glycolysis: two molecules of pyruvic acid per one molecules of glucose d. Pyruvate dehydrogenase complex: two molecules of acetyl-coa from one molecule of pyruvic acid 31. Which of the following best describes the function of a photosystem? a. It generates glucose from carbon dioxide and water. b. It generates a proton gradient in order to produce ATP. c. It generates NADH and FADH2 from the oxidation of acetyl-coa. d. It absorbs light energy and converts it to ATP and NADPH. 32. Which of the following is not true about metabolic regulation of a cell? a. Cells close all channels in the membrane if no energy sources are need. b. Cells use allosteric sites on enzymes to control enzymatic activity. c. Feedback inhibition prevents cells from producing products in excess. d. In metabolic channeling, the regulation of metabolic pathways is controlled by the location of metabolites and enzymes involved. 33. Which of the following statements is true? a. Isoenzymes are the same enzymes that catalyze different reactions. b. In allosteric regulation, effector molecules bind reversibly and covalently. c. In a branched pathway, one end product in excess will inhibit the first step in the pathway that leads to the production of that particular end product.

5 d. GTP provides energy for lipid synthesis. e. The ETC in bacterial cells is located in the cytoplasm. 34. Which reaction would be catalyzed by a ribozyme? a. The phosphorylation of glucose b. Deamination of trna c. Reduction of O2 to form H2O d. Peptide bond formation 35. Select all the groups that are used to covalently modify an enzyme s activity. a. Carbonyl b. Phosphoryl c. Adenyl d. Carboxyl e. Methyl 36. Which of the following statements is true? a. Nitrification of ammonia happens when ammonia is converted to nitrite and then converted to nitrate by the nitrogen-fixing bacteria. b. Fatty acids are metabolized by the alpha-oxidation pathway. c. While breaking down fatty acids, two carbon units are released as acetyl-coa. d. Oxygen is required for the process of cellular respiration. 37. Which is a carbon source for photolithoautotroph? a. Light b. Inorganic carbon c. Carbon dioxide d. Sulfur compounds 38. How many molecules of ATP are needed to reduce CO2 to carbohydrate during the dark and spooky reactions of photosynthesis? a. 1 b. 2 c. 3 d. 4 e Which is true about photosynthesis? a. All prokaryotic photosynthesizes are anoxygenic. b. In the process of noncyclic photophosphorylation, photosystems I and II are both required. c. Photosynthetic electron transport in cyanobacteria occurs in the cytoplasm. d. Fueling reactions are anabolic reactions. 40. Aerobic respiration, anaerobic respiration, and fermentation are examples of: a. Photolithoautrotrophic metabolism b. Photoorganotrophic metabolism c. Chemolithotrophic metabolism d. Chemoorganoheterotrophic metabolism 41. Which of the statements is true? Select all that apply. a. Fermentation includes the electron transport chain. b. Substrate-level phosphorylation produces more ATP than oxidative phosphorylation. c. Dissimilatory nitrate reduction is when nitrogen is no longer available for producing precursor metabolites, since nitrate was used as a final electron acceptor by bacteria. d. Accessory pigments are involved in regulating the Calvin Cycle. e. Accessory pigments extend the spectrum of wavelengths that drive photosynthesis. 42. How is oxidative phosphorylation similar to photophosphorylation?

6 a. The energy source is organic compounds. b. Water is split to provide electrons. c. They both require oxygen to occur. d. The proton motive force is generated. e. ATP synthase enzyme phosphorylates AMP to make ATP. 43. In photophosphorylation, the source of energy is a. Light b. Oxygen c. Carbon compounds d. Nitrogen e. ATP 44. Organisms can synthesize ATP by oxidative phosphorylation: a. When they ferment b. When they oxidize glucose to pyruvate c. When they pass electrons to oxygen through an ETC containing cytochromes d. When they pass electrons from the oxidation of chlorophyll through an ETC e. All of the above 45. The is the election donor in a redox reaction. a. Reductant b. Oxidizing Agent c. Oxidant d. Both B & C 46. Select all the statements that are true. a. Plants and animals use the ED pathway for glycolysis. b. Chemiosmosis produces the most ATP during aerobic respiration. c. The terms phototroph and chemotroph refer to an organism s energy source, not carbon or electron source. d. In the light-dependent reaction of plants, water is split to form oxygen. e. The theoretical max net gain of ATP per glucose metabolized aerobically in eukaryotes is In oxidative phosphorylation during cell respiration, the source of energy is, while in photophosphorylation, the source of energy is. a. Highly reduced organic compounds; light b. Light; highly reduced organic compounds c. NADH; NADPH d. Electron transport chain; chlorophyll e. ATP; light 48. Photoheterotrophs that use light to generate ATP, but do not fix CO2. Select all that apply with this statement. a. They would best be described as photosynthesis b. They would use both the light reactions and the dark reactions c. They would best be described as phototrophic d. They would use the light reactions but not the dark reactions 49. Light is required for the light dependent reactions because: a. It is a source for electrons. b. It splits the water molecule. c. It energizes the electrons in the reaction center, leading to the proton motive force. d. It splits ATP molecules which generates the energy necessary to power the light independent reactions. Answer #50 with the following information: I. The number of ATP produced by a cell from glucose when metabolizing it by fermentation means.

7 II. The amount of ATP produced by a cell from glucose by metabolizing it by aerobic metabolism means. a. I is greater than II b. I is less than II c. I is exactly or approximately equal to II 51. In the TCA cycle, two carbons in the form of are added to oxaloacetate. a. Succinate b. Ethanol c. Malate d. Carbon dioxide e. Acetyl-coA 52. Select all the names that are identical to each other and are referring to the same process. a. Calvin cycle b. TCA Cycle c. Citric Acid Cycle d. Krebs cycle e. Carbon Cycle NOTE FROM ROMINA: As always, not everything on this exam will be on your exam; don t forget to study anything not covered on this exam, because it may still show up, and my practice exam doesn t cover or reflect every single thing on your exam. Don t ignore your textbook please! It can be very helpful for giving you in-depth knowledge of sections in the powerpoint. Use the self study option on your homework to practice with additional questions. Know all your vocabulary and be able to solve the redox math problems!! Don t forget to check out the study guides, worksheets, Jeopardy, and pictures posted on the SI website under Exam Three Content please don t overlook Dr. Ambivero s TCA Cycle Worksheet on Canvas! From me to you, YOU CAN DO IT and I believe in you and your abilities and intelligence and I see how hard so many of you work. Don t let yourself get overwhelmed from the information. Take it step-by-step and slow; remember this: you know what you know that you know, and you know more than you think!!! I just wanted to say how great it has been working with all of you. Don t forget to have a fun and safe Halloween! :)

Microbial Metabolism. PowerPoint Lecture Presentations prepared by Bradley W. Christian, McLennan Community College C H A P T E R

Microbial Metabolism. PowerPoint Lecture Presentations prepared by Bradley W. Christian, McLennan Community College C H A P T E R PowerPoint Lecture Presentations prepared by Bradley W. Christian, McLennan Community College C H A P T E R 5 Microbial Metabolism Big Picture: Metabolism Metabolism is the buildup and breakdown of nutrients