Microbiology Chapter 5 – Flashcards

Which of the following statements is MOST accurate concerning metabolism? A) Metabolism is the digestion of nutrients to release energy. B) Metabolism is the assembly of small molecules into macromolecules. C) Metabolism is all the chemical reactions of an organism, both anabolic and catabolic. D) Metabolism is the production and expenditure of chemical energy. E) Metabolism is the assembly of macromolecules into cellular structures.

Anabolic reactions may be characterized as A) exergonic. B) breaking large molecules into smaller molecules. C) forming large molecules from smaller molecules. D) producing ATP. E) breaking large molecules into smaller molecules to produce ATP

3) Which of the following statements concerning reduction reactions is FALSE? A) An electron acceptor gains an electron. B) They are coupled with oxidation reactions. C) They frequently involve electron carrier molecules. D) An electron acceptor becomes more positively charged. E) A molecule gains a hydrogen atom.

The molecule that an enzyme acts upon is known as its A) substrate. B) coenzyme. C) apoenzyme. D) holoenzyme. E) catalyst.

Which of the following processes utilize inorganic phosphate? A) photophosphorylation B) oxidative phosphorylation C) substrate-level phosphorylation D) both photophosphorylation and substrate-level phosphorylation E) both photophosphorylation and oxidative phosphorylation

Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as A) allosteric inhibition. B) competitive inhibition. C) excitatory allosteric control. D) noncompetitive inhibition. E) feedback inhibition.

Which of the following is required for holoenzyme function? A) a protein cofactor B) a coenzyme C) an allosteric inhibitor D) a substrate E) an activator

The catalytic component of a ribozyme is A) a cofactor. B) an apoenzyme. C) a coenzyme. D) FADH. E) RNA.

NAD (nicotinamide adenine dinucleotide) is required for many ________ reactions. A) ribozyme B) catabolic C) transfer D) oxidation-reduction E) phosphorylation

Which of the following is TRUE concerning the structure and function of enzymes? A) All enzymes bind cofactors necessary for their function. B) An apoenzyme is a combination of a cofactor bound to a holoenzyme. C) Enzymes can function at a wide range of pH. D) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme. E) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.

Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore, it is ________ pathway. A) an exergonic B) an endergonic C) an oxidative D) a reductive E) neither an exergonic nor an endergonic

Isomerases catalyze reactions in which A) biomolecules are assembled from smaller molecules. B) biomolecules are broken down into their component parts. C) groups are transferred from one molecule to another. D) atoms in biomolecules are rearranged. E) biomolecules are oxidized or reduced.

In reactions catalyzed by oxidoreductases an electron donor is A) oxidized. B) reduced. C) synthesized. D) degraded. E) unaltered.

Hydrolases are generally involved in ________ reactions. A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) oxidation-reduction

Changes in temperature or pH can cause enzymes to lose activity. What is a common feature of these two effects? A) Temperature and pH affect the rate of substrate binding. B) Temperature and pH both induce an enzyme to lose its precise three-dimensional shape. C) Temperature and pH change the activation energy of the reaction. D) Temperature and pH change the ionization state of cofactors. E) There is no common mechanism of temperature and pH effects on enzyme activity.

The arrow indicates the only protein component of this complex. This illustration represents a(n) A) apoenzyme. B) coenzyme. C) holoenzyme. D) ribozyme. E) ubiquinone.

Which of the following produces NADPH? A) the pentose phosphate pathway only B) the Entner-Doudoroff pathway only C) the Embden-Meyerhof pathway only D) both the Embden-Meyerhof and Entner-Doudoroff pathways E) both the pentose phosphate and Entner-Doudoroff pathways

Which of the following statements concerning glycolysis is TRUE? A) Glycolysis produces ATP by oxidative phosphorylation. B) Glycolysis occurs in the cell membranes of bacteria. C) Glycolysis both requires the input of ATP and produces ATP. D) Glycolysis is an alternative to fermentation. E) Ribulose 5-phosphate is an intermediate of glycolysis.

Which of the following can be the final electron acceptor in anaerobic respiration in bacteria? A) nitrate only B) pyruvic acid only C) sulfate only D) both nitrate and sulfate E) nitrate, pyruvic acid, and sulfate

Heme complexed with iron is found in ________ of the electron transport chain. A) flavoproteins B) metal-containing proteins C) ribozymes D) cytochromes E) ubiquinones

Changes in ________ can be useful in analyzing microbes' ability to ferment carbohydrates. A) pH B) oxygen use C) osmotic pressure D) smell E) temperature

Which of the following is a fermentation product useful in the manufacture of cheese? A) acetic acid B) ammonia C) ethanol D) lactic acid E) pyruvic acid

How many ATP molecules can theoretically be produced from the NADH generated by the catabolism of a molecule of glucose during aerobic respiration? A) 34 B) 30 C) 38 D) 36 E) 4

The metabolic processes called fermentation A) produce substrates for the Krebs cycle. B) are alternatives for the pentose phosphate pathway. C) use an organic molecule as a final electron acceptor. D) occur only when oxygen is readily available. E) produce substrates for glycolysis.

In aerobic non-photosynthetic organisms, the majority of ATP is generated by A) glycolysis reactions. B) catabolic reactions. C) the Calvin-Benson cycle. D) oxidation-reduction reactions. E) substrate-level phosphorylation.

Many metabolites for anabolic pathways are produced by the ________ pathway. A) pentose-phosphate B) Entner-Doudoroff C) beta-oxidation D) chemiosmosis E) glycolytic

Which of the following is the final electron acceptor in aerobic respiration? A) acetic acid B) oxygen C) carbonate D) nitrate E) sulfate

During the synthesis of acetyl-CoA from pyruvic acid, ________ is produced. A) ATP B) NADH C) FADH2 D) H2O E) acetic acid

Substrate-level phosphorylation occurs during the ________ stage(s) of glycolysis. A) energy-investment B) lysis C) energy-conservation D) energy-investment and energy-conservation E) energy-investment, lysis, and energy-conservation

The production of NADH takes place during the ________ stage(s) of glycolysis. A) energy-conservation B) energy-investment C) lysis D) lysis and energy-investment E) energy-investment and energy-conservation

Glycolysis begins with a(n) ________ stage(s). A) energy-conservation B) lysis C) energy-investment D) lysis and energy-conservation E) energy-investment and conservation

Identify the processes of glucose metabolism represented in Figure 5-1. A) A = electron transport chain, B = Krebs cycle, C = glycolysis, D = fermentation B) A = glycolysis, B = fermentation, C = Krebs cycle, D = electron transport chain. C) A = fermentation, B = glycolysis, C = Krebs cycle, D = electron transport chain D) A = glycolysis, B = Krebs cycle, C = fermentation, D = electron transport chain E) A = glycolysis, B = Krebs cycle, C = electron transport chain, D = fermentation

All of the following are ways in which cells regulate metabolism EXCEPT A) feedback inhibition by end products. B) synthesis or degradation of membrane transport proteins. C) isolation of various enzymes within membranous organelles. D) synthesis of a catabolic enzyme only when its substrate is available. E) use of the same coenzymes for anabolic and catabolic reactions that share substrate molecules

Chemical reactions that are reversible, proceeding anabolically or catabolically, are called A) glycolytic. B) light-independent. C) synthetic. D) cyclic. E) amphibolic.

If a cell reverses the process of beta-oxidation, which of the following molecules will it make? A) glycerol B) amino acids C) fatty acids D) nucleotides E) starch

The process of ________ produces amino acids from precursor metabolites and ammonia. A) amination B) transamination C) reduction D) polymerization E) deamination

The conversion of amino acids to carbohydrates is an example of A) amination. B) gluconeogenesis. C) substrate-level phosphorylation. D) beta-oxidation. E) electron transport.

Which of the following products of glucose catabolism is a substrate for fatty acid synthesis? A) acetyl-CoA B) pyruvic acid C) phosphoglyceric acid D) oxaloacetate E) succinyl-CoA

A catabolic process which occurs in eukaryotic mitochondria is A) deamination. B) beta-oxidation. C) the Entner-Doudoroff pathway. D) fermentation. E) the Calvin-Benson cycle.

Which of the following is a by-product of the catabolism of proteins? A) lactic acid B) acetyl-CoA C) proteases D) ammonia E) carbon dioxide

Beta-oxidation produces a substrate of the A) pentose phosphate pathway. B) Entner-Doudoroff pathway. C) Embden-Meyerhof pathway. D) Krebs cycle. E) Calvin-Benson cycle

Which of the following is/are common to chemiosmosis and the light-dependent reactions of photosynthesis? A) reduction of NADP+ only B) electron transport only C) a proton gradient only D) both electron transport and a proton gradient E) electron transport, a proton gradient, and reduction of NADP+

The habitat of a photosynthetic organism is largely determined by the A) amount of available oxygen. B) products of its light-independent reactions. C) carbohydrates it can metabolize. D) amount of available hydrogen. E) chlorophylls it produces

Photosystems are assembled in A) thylakoids. B) grana. C) stroma. D) cristae. E) cytoplasm.

Oxygenic photosynthesis requires A) the Entner-Doudoroff pathway. B) the pentose phosphate pathway. C) photosystem II. D) substrate-level phosphorylation. E) glycolysis.

What is the major product of the Calvin-Benson cycle that can then be used to form glucose? A) carbon dioxide (CO2) B) adenosine triphosphate (ATP) C) ribulose bisphosphate (RuBP) D) glyceraldehyde 3-phosphate (G3P) E) NADPH

The assembly of carbon dioxide and water into carbohydrates occurs in the process known as A) fermentation. B) oxidation. C) photosynthesis. D) gluconeogenesis. E) chemiosmosis.