MCB Exam 3 Quiz Questions With Correct Solutions

MCB Exam 3 Quiz Questions With Correct Solutions /.How do enzymes increase the rate of a biochemical reaction? By lowering the activation energy. By increasing the standard free energy. By increasing the activation energy. By lowering the ΔG0'. By lowering the reduction potential. /.Which of these is TRUE for a chemoorganoheterotroph? Uses organic carbon as an electron source and inorganic carbon as a carbon source. Uses inorganic carbon as an energy source and a carbon source. Uses inorganic carbon as an energy source and organic carbon as a carbon source. Uses inorganic carbon as an electron source and organic carbon as a carbon source. Uses organic carbon as an electron source and a carbon source. /.The standard reduction potential (E0') for ferredoxin (Fdox/Fdred) is (-0.43 V). Based on this, which of these would you expect to be true? Reduced ferredoxin to be a good electron acceptor. Reduced ferredoxin to be a good electron donor. Oxidized ferredoxin to be a good electron donor. Oxidized ferredoxin to be a good electron acceptor. Cannot be determined without knowledge of the ΔG0'. /.Which of these is an example of a coenzyme? NAD+ iron glucose cytochrome c oxidase kinase /.The most common lipids in the cell are synthesized from ___________ and ____________. fatty acids and sterol fatty acids and glycerol fatty acids and hopanoids glycerol and hopanoids hopanoids and sterols /.Nitrification is a two-step process to oxidize nitrate into ammonium a two-step process to oxidize ammonium into nitrate a fermentation reaction the conversion of nitrogen gas into nitrate /.Oxidative phosphorylation requires ALL of the following for energy production EXCEPT: electrons from NADH. pyruvate synthase. membrane-associated electron transport chain. a proton motive force. an ATP synthase. /.Some anoxygenic photosynthetic bacteria are able to use _______ as an electron source. CO2 H2O Fe3+ H2S nitrate /.What is denitrification? The assimilation of ammonia by the cell. The reduction of dinitrogen to nitrate. The reduction of nitrate to dinitrogen. The production of nitrate from ammonia. The assimilation of nitrate by the cell. /.Lactic acid is a common fermentation product. It is produced when ___________ is reduced by electrons received from NADH. pyruvate acetyl-CoA ethanol glucose 3-phosphoglyceraldehyde /.Which of these is the most widely used form of energy in cell processes? glucose ATP pyruvate citrate NAH /.The biochemical reaction, phosphoenolpyruvate (PEP) + ADP → Pyruvate + ATP, is an example of which of these? Substrate-level phosphorylation. An oxidation/reduction reaction. An aldolase catalyzed reaction. Oxidative phosphorylation. An electron transport reaction. /.Where is the reaction center of photosystems located? Either in the cytoplasm or within a membrane. In the cytoplasm. Within a biological membrane. In the periplasmic space. Within the cell wall. /.Which of these best describes assimilatory sulfate reduction? The reduction of sulfate to elemental sulfur. An energy yielding process. The reduction of sulfate for incorporation into cellular material. The reduction of sulfate to sulfide for excretion by the cell. A type of anaerobic respiration. /.Which statement is TRUE with respect to the electron transport system? The electron transport system accepts electrons directly from glucose. ATP is produced by a process called substrate-level phosphorylation. In bacteria, the electron transport system is located in the cytoplasm. In prokaryotes, protons are transported into the cell as electrons move through the system. A proton motive force is generated as electrons move through the system to a terminal acceptor. /.Which is the major nitrogen reservoir on Earth? organic matter in soil microbes atmosphere ocean biomass plants /.How can denitrification rates in soil be reduced? By adding potash to the soil. By adding lime to the soil. By flooding the soil with water. By keeping the soil well aerated. By adding ammonia to the soil. /.Most of the organic matter in soil comes from the decomposition of what material? animals algae plantae