Ch.8 Metabolism

Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities? A) E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides. B) E. coli will be unable to build the peptidoglycan it needs for its cell wall. C) All amino acids are "essential" to E. coli. D) E. coli will be unable to perform amination. E) E. coli will use salvage pathways to make nucleotides.

A) E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.

The main goal of fermentation is to sustain ATP production by glycolysis. This is accomplished by A) passing the electrons on NADH to pyruvic acid, regenerating NAD+ so glycolysis can continue. B) enables the cell to use its respiratory chain without oxygen being available. C) producing acids and alcohols which the microorganism can use as an alternative nutrient source when glucose is not available. D) producing acids which lower cellular pH to promote more efficient ATP recharge. E) diverting glycolysis intermediates into the pentose phosphate pathway.

A) Passing the electrons on NADH to pyruvic acid, regenerating NAD+ so glycolysis can continue

What is the advantage of a rapid identification tool such as the API system? A) allows a high volume of samples to be processed quickly and reliably and can often be read using an automated reader B) allows a high volume of samples to be processed quickly and reliably and can be inoculated with a mixed or unpurified culture C) allows a high volume of samples to be processed quickly and reliably D) can be inoculated with a mixed or unpurified culture E) can often be read using an automated reader

A) allows a high volume of samples to be processed quickly and reliably and can often be read using an automated reader

Which structural and functional feature(s) listed are key to an enzyme's activity? A) contains an active site where the enzyme can interact with a specific substrate B) consumed each time a reaction takes place C) consumed each time a reaction takes place and contains an active site where the enzyme can interact with a specific substrate D) consumed each time a reaction takes place and consists of a three-dimensional protein structure that interacts with a substrate in a fixed "lock-and-key" model E) consists of a three-dimensional protein structure that interacts with a substrate in a fixed "lock-and-key" model

A) contains an active site where the enzyme can interact with a specific substrate

Besides biochemical tests, which techniques are also useful for identifying a bacterial specimen? A) microscopy and molecular genetics techniques and observation of general culture characteristics B) observation of general culture characteristics C) molecular genetics techniques D) microscopy E) microscopy and observation of general culture characteristics

A) microscopy and molecular genetics techniques and observation of general culture characteristics

Enzymes can lower the activation energy of a chemical reaction by A) raising the temperature so that reactants collide more forcefully. B) properly positioning reactants and stabilizing the transition state. C) properly positioning reactants and raising the temperature so that reactants collide more forcefully. D) stabilizing the transition state. E) properly positioning reactants.

B) properly positioning reactants and stabilizing the transition state.

A pathway that functions simultaneously in both anabolism and catabolism is termed A) cyclic. B) allosteric. C) amphibolic. D) biosynthetic. E) redox.

C) Amphibolic

Cyanide is a poison which prevents the last carrier in the electron transport chain (cytochrome C oxidase) from transferring the electron to the final electron acceptor. Which of the following would not be a consequence of exposure to this poison? A) Movement of electrons through the chain would stop. B) Protons would no longer be pumped outside the membrane. C) ADP would no longer be recharged to form ATP. D) Carbon dioxide would continue to be generated. E) Glycolysis, the intermediate reaction, and the Krebs cycle would stop as the cell would run out of the necessary oxidized coenzymes NAD+ and FAD.

D) Carbon dioxide would continue to be generated.

Which is not one of the categories used to classify an organism based on its nutrition? A) source of energy for making ATP and ability to run either catabolic or anabolic pathways B) source of energy for making ATP C) ability to fix carbon D) initial source of electrons for reduction reactions E) ability to run either catabolic or anabolic pathways

E) ability to run either catabolic or anabolic pathways

Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle? A) carbon dioxide B) ATP C) pyruvic acid D) NADH E) acetyl CoA

E) acetyl CoA

The intermediate(s) needed to synthesize lipids from sugar catabolism is (are) A) acetyl CoA. B) citric acid and dihydroxyacetone phosphate (DHAP). C) citric acid. D) dihydroxyacetone phosphate (DHAP). E) acetyl CoA and dihydroxyacetone phosphate (DHAP)

E) acetyl CoA and dihydroxyacetone phosphate (DHAP)

Ribozymes are enzymes which A) are made of RNA. B) may have medical applications as antiviral therapies. C) work on RNA substrates. D) are made of RNA and work on RNA substrates. E) are made of RNA, work on RNA, and may have medical applications as antiviral therapies.

E) are made of RNA, work on RNA, and may have medical applications as antiviral therapies.

Bacteria that live in deep ocean volcanic vents form the base of an ecosystem that exists without light. They obtain electrons from hydrogen sulfide compounds dissolved in the vent water, and synthesize sugars from carbon, hydrogen, and oxygen. The bacteria would be classified as A) chemolithoheterotrophs. B) photolithoautotrophs. C) photoorganoheterotrophs. D) chemoorganoheterotrophs. E) chemolithoautotrophs.

E) chemolithoautotrophs.

Biochemical tests are useful to microbiology because A) they can be used to identify microbes. B) they can be used to identify microbes and to identify potential pathogens in clinical samples. C) they can be used to detect metabolic end-products, intermediates, or particular enzymes. D) they can be used to identify potential pathogens in clinical samples. E) they can be used to identify microbes and to identify potential pathogens in clinical samples and they can be used to detect metabolic end-products, intermediates, or particular enzymes.

E) they can be used to identify microbes and to identify potential pathogens in clinical samples and they can be used to detect metabolic end-products, intermediates, or particular enzymes.

Catabolic reactions are hydrolytic and exergonic while anabolic reactions are biosynthetic and endergonic.

true

The term ________ includes both the chemical reactions that organisms use to break down substances to release energy, as well as the reactions that use released energy to build new substances. A) oxidation-reduction B) metabolism C) catabolism D) biosynthesis E) anabolism

B) metabolism

Which is the key difference between aerobic and anaerobic respiratory chains? A) Aerobic respiratory chains that accept electrons depend on membrane-associated electron carrier molecules that carry out redox reactions while anaerobic chains use cytoplasm-associated molecules that carry out redox reactions. B) Aerobic respiratory chains always use oxygen as the final electron acceptor while anaerobic respiratory chains may use a variety of inorganic substances other than oxygen as the final electron acceptor. C) Aerobic respiratory chains are organized so that electrons are passing from a higher to lower energy state while anaerobic chains are organized so that electrons are passing from a lower to a higher energy state. D) Aerobic respiratory chains accept electrons from both NADH and FADH2 while anaerobic chains only accept electrons from FADH2. E) Aerobic respiratory chains are found in prokaryotic cells only while anaerobic chains are found in eukaryotic cells only.

B) Aerobic respiratory chains always use oxygen as the final electron acceptor while anaerobic respiratory chains may use a variety of inorganic substances other than oxygen as the final electron acceptor.

Enzymes are necessary for cells because A) enzymes slow down chemical reactions that would otherwise occur too quickly to facilitate life. B) enzymes allow chemical reactions to occur under physiological conditions and within a time frame conducive to life. C) enzymes allow chemical reactions to occur under physiological conditions. D) enzymes allow chemical reactions to take place that would otherwise be impossible. E) enzymes allow chemical reactions to occur quickly enough to facilitate life.

B) Enzymes allow chemical reactions to occur under physiological conditions and within a time frame conducive to life

Which category of biochemical tests is incorrectly matched with its description? A) Fermentation tests: Detects various fermentation end-products or specific pathways B) Oxidase and catalase tests: Identifies the presence of enzymes related to anaerobic respiratory chains C) Amino acid catabolism tests: Detect specific enzymes involved in catabolism of amino acids D) Exoenzyme tests: Detect enzymes involved in extra-cellular breakdown of macromolecules E) Rapid identification techniques: Provides a semi-automated process of running multiple types of tests with a single inoculation

B) Oxidase and catalase tests: Identifies the presence of enzymes related to anaerobic respiratory chains

Which phosphorylation mechanism for recharging ADP to ATP is incorrectly matched with its description? A) Photophosphorylation: Passes electrons energized by solar energy through an electron transport chain B) Substrate-level phosphorylation: A phosphate is transferred to ADP from a high-energy substrate after passing through an electron transport chain. C) Oxidative Phosphorylation: Passes electrons stripped from nutrients through an electron transport chain D) The descriptions for oxidative phosphorylation and photophosphorylation are incorrectly matched. E) The descriptions for oxidative phosphorylation, photophosphorylation, and substrate-level phosphorylation are incorrectly matched.

B) Substrate-level phosphorylation: A phosphate is transferred to ADP from a high-energy substrate after passing through an electron transport chain.

Catabolic reactions A) are endergonic. B) are hydrolytic and involve breaking down larger molecules into smaller molecules. C) are hydrolytic. D) involve breaking down larger molecules into smaller molecules. E) are endergonic and are hydrolytic.

B) are hydrolytic and involve breaking down larger molecules into smaller molecules.

Catabolic and anabolic reactions depend upon each other, as evidenced by which of the following statements? A) Catabolic reactions release energy which is used by anabolic reactions B) Anabolic reactions split bigger molecules into smaller components, which are in turn used by catabolic reactions to build more complex molecules. C) Catabolic reactions split bigger molecules into smaller components which are used by anabolic reactions to build more complex molecules AND catabolic reactions release energy which is used by anabolic reactions. D) Anabolic reactions split bigger molecules into smaller components, which are in turn used by catabolic reactions to build more complex molecules AND catabolic reactions release energy which is used by anabolic reactions. E) Catabolic reactions split bigger molecules into smaller components which are used by anabolic reactions to build more complex molecules.

C) Catabolic reactions split bigger molecules into smaller components which are used by anabolic reactions to build more complex molecules AND catabolic reactions release energy which is used by anabolic reactions.

Which coenzyme is incorrectly matched with its function? A) Coenzyme A: Metabolism of pyruvic acid and lipids B) THF / DHF: Make purines and pyrimidines C) Cobalamin: Transfer of CO2 groups D) FAD / FMN: Electron transfers E) NAD+ /NADP+: Electron transfers

C) Cobalamin: Transfer of CO2 groups

Which of the following pathways are operational in a cell growing via fermentation? A) Krebs cycle B) glycolysis, intermediate step, and the Krebs cycle C) glycolysis D) intermediate step E) glycolysis and intermediate step only

C) Glycolysis

Which statement is not true about the pentose phosphate pathway? A) It converts 5-carbon sugars into 3- and 6-carbon for use in glycolysis. B) It can be used in part by photosynthetic cells to build glucose from carbon dioxide. C) It allows cellular respiration to occur without the need for oxygen. D) It diverts glucose-6-phosphate from glycolysis to synthesize 5-carbon sugars needed for nucleotides. E) It produces the coenzyme NADPH needed for anabolic pathways

C) It allows cellular respiration to occur without the need for oxygen.

Oxidation of nutrients by cells results in A) a requirement for energy which can be used to recharge ADP to ATP. B) a release of energy, which is released by converting ATP to ADP. C) a release of energy, which can be used to recharge ADP to ATP. D) a requirement of energy which can be obtained by converting ATP to ADP. E) either a release or a requirement for energy depending on what type of nutrient is available.

C) a release of energy, which can be used to recharge ADP to ATP.

Which of the following does not describe cellular respiration? A) involves a transfer of energy into the bonds of ATP B) occurs in part in the mitochondria of eukaryotic cells C) may include multiple pathways including glycolysis, an intermediate step, the Krebs cycle and fermentation D) collection of reactions that extract energy from food using redox reactions E) may occur in both prokaryotic and eukaryotic cells

C) may include multiple pathways including glycolysis, an intermediate step, the Krebs cycle and fermentation

Which of the following factors may influence an enzyme's activity by altering its three-dimensional structure? A) temperature B) pH C) pH and temperature only D) competitive inhibitor E) pH, temperature, and competitive inhibitor

C) pH and temperature only

In the typical ATP-ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored? A) the terminal two phosphate groups B) adenine C) the terminal phosphate group D) ribose E) all three phosphate groups

C) the terminal phosphate group

One of the ways that cells balance anabolism and catabolism is to A) use separate coenzymes such as NAD+ vs. NADP+ for catabolic vs. anabolic pathways. B) use the same enzyme to run a reaction in both the catabolic and anabolic direction and use feedback inhibition to shut down a pathway that is not needed. C) use feedback inhibition to shut down a pathway that is not needed and use separate coenzymes such as NAD+ vs. NADP+ for catabolic vs. anabolic pathways. D) use feedback inhibition to shut down a pathway that is not needed. E) use the same enzyme to run a reaction in both the catabolic and anabolic direction.

C) use feedback inhibition to shut down a pathway that is not needed and use separate coenzymes such as NAD+ vs. NADP+ for catabolic vs. anabolic pathways.

What is the relationship between the ATP-ADP cycle and catabolic and anabolic reactions? A) Energy released from catabolic reactions is used to break ATP down to ADP. Then the energy needed for anabolic reactions is released by to recharging ADP back to ATP. B) Energy released from anabolic reactions is used to recharge ADP back to ATP. Then the energy needed for catabolic reactions is released by breaking ATP down to ADP. C) Catabolic reactions require energy, which is provided by anabolic reactions. ADP is recharged to ATP by energy from anabolic reactions. D) Energy released from catabolic reactions is used to recharge ADP back to ATP. Then the energy needed for anabolic reactions is released by breaking ATP down to ADP. E) There is no relationship between the ATP-ADP cycle and catabolic and anabolic reactions.

D) Energy released from catabolic reactions is used to recharge ADP back to ATP. Then the energy needed for anabolic reactions is released by breaking ATP down to ADP.

In order to harvest energy from polysaccharides, lipids or proteins, cells must use ________ to break down these large macromolecules extracellularly before bringing them into the cell. A) glycogenesis B) deamination C) beta-oxidation D) exoenzymes E) Entner-Doudoroff pathway

D) Exoenzymes

Sequence the following events as they occur at the electron transport chain. I. Protons accumulate on one side of the membrane to form a proton motive force. II. The coenzymes NADH and FADH2 drop off electrons to the carriers in the respiratory chain. III. Protons flow through ATP synthase which captures the energy of the flowing protons and uses it to recharge ADP to ATP. IV. Electrons moving through the chain release energy to pump proteins across the membrane where the carrier proteins are found. A) I ,III , IV ,II B) I ,II , III ,IV C) III ,II , IV ,I D) II ,IV , I ,III E) II ,I ,IV ,III

D) II ,IV , I ,III

Of the following fermentation pathways, which can be carried out by human muscle cells? A) lactic acid: heterolactic B) alcoholic C) mixed acid D) lactic acid: homolactic E) butanediol

D) Lactic acid: homolactic

Consider this summarized chemical reaction for aerobic cellular respiration: C6H12O6 + 6 O2 + 38 ADP + 38 PO3 2- 6 CO2 + 6 H2O + 38 ATP What would be different in a summarized chemical reaction for anaerobic cellular respiration? A) The oxygen would be replaced by a different inorganic compound. B) The numbers of ADP, PO3 2-, and ATP used / generated would be different. C) The water would be replaced by a different reduced product. D) The numbers of ADP, PO3 2-, and ATP used / generated would be different and the oxygen would be replaced by a different inorganic compound and the water would be replaced by a different reduced product. E) The oxygen would be replaced by a different inorganic compound and the water would be replaced by a different reduced product.

D) The numbers of ADP, PO3 2-, and ATP used / generated would be different and the oxygen would be replaced by a different inorganic compound and the water would be replaced by a different reduced product.

Anabolic reactions A) are endergonic. B) involve dehydration synthesis. C) are endergonic and involve breaking down larger molecules into smaller molecules. D) are endergonic and involve dehydration synthesis. E) involve breaking down larger molecules into smaller molecules.

D) are endergonic and involve dehydration synthesis

When electrons are removed from nutrients via an oxidation reaction, the coupled reduction reaction may be A) NADH NAD+. B) NAD+ NADH. C) FAD FADH2. D) either FAD FADH2 or NAD+ NADH. E) either NAD+ NADH or NADH NAD+.

D) either FAD FADH2 or NAD+ NADH.

Gluconeogenesis A) can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism. B) is an example of biosynthesis. C) is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism. D) is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism and an example of biosynthesis. E) is building glucose from non-sugar starting materials.

D) is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism and an example of biosynthesis.

Which of the following statements correctly describes what happens during chemiosmosis? A) Protons are added directly to ADP to recharge it to ATP. B) Protons flow through the ATP synthase enzyme from the side of the membrane where they are lower in concentration to the side where they are higher in concentration. C) The purpose is to generate water from oxygen. D) Only electrons from the reduced carrier NADH are deliver to the electron transport chain; the reduce carrier FADH2 takes its electrons elsewhere. E) The energy of protons flowing through the ATP synthase enzyme powers the recharge of ADP to ATP

E) The energy of protons flowing through the ATP synthase enzyme powers the recharge of ADP to ATP