Microbio Chapter 5 - Microbial Metabolism

True or False: In general, ATP is generated in catabolic pathways and expended in anabolic pathways

True

True or False: Once an enzyme has converted substrates into products, the active site revert back to its original form

True

True or False: an apoenzyme that loses its coenzyme subunit will be non-functional

True

True or False: both respiration and photosynthesis require the use of an electron transport chain

True

True or False: glycolysis is utilized by cells in both respiration and fermentation

True

What is the purpose of fermentation? A. to produce ATP B. to generate energy in the absence of oxygen C. to be an alternative to glycolysis D. to regenerate NAD+ from NADH

D. to regenerate NAD+ from NADH

True or False: The use of enzymes is necessary to increase the activation energy requirements of a chemical reaction

False

True or False: the pentose phosphate pathway can be characterized as an anabolic pathway

False

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

Glucose

Match the words in the left column to the appropriate blanks in the sentences on the right. Words will be used more than once. anabolic catabolic

1. Catabolic pathways break down macromolecules into simple component 2. Catabolic pathways release energy. 3. Anabolic pathways build up macromolecules by combining simpler molecules. 4. Anabolic pathways require energy. 5. Catabolic pathways provide the building blocks and the energy needed for anabolic reactions. 6. Some energy released by catabolic reactions is stored in the form of chemical bonds in ATP. 7. Catabolic reactions couple with ATP synthesis. 8. Anabolic reactions couple with ATP breakdown.

What is the most acidic place in the figure? A B C D E

A

During the infection, there are many different environments that P. multocida will encounter. In order to cause an infection like the one in Sam's forearm, P. multocida must regulate its metabolic pathways in order to adapt to the changing environments. The process of glycolysis is regulated at several steps by allosteric inhibition. Which of the following are features of allosteric inhibition? A. Allosteric inhibition can be reversed. B. Allosteric inhibition can be irreversible. C. The allosteric inhibitor binds to a site distinct from the active site resulting in decreased affinity of the enzyme for the substrate. D. Allosteric inhibition can be overcome by increasing the amount of substrate in the reaction. E. In order to function, allosteric inhibitors must have structural similarity to the enzyme substrate.

A, B, & C

Compare and contrast three metabolic pathways by choosing whether the statement applies to aerobic respiration. Check all that apply. A. End products are CO2 and H2O B. Process includes glycolysis C. Process involves the Krebs cycle D. Between 2 and 38 ATP are produced per molecule of glucose input. E. Much or most of the ATP produced is produced by oxidative phosphorylation. F. A total of 38 ATP are produced per molecule of glucose input. G. End products may include lactic acid or ethanol. H. A total of 2 ATP are produced per molecule of glucose input. I. Process involves electron transport and chemiosmosis J. The coenzyme NAD+ plays an important role in the pathway. K. Can generate ATP in the absence of O2.

A, B, C, E, F, I, & J

Which of the following is true of anabolic reactions? A. Anabolic reactions use ATP and small substrates as building blocks to synthesize larger molecules. B. Anabolic reactions release energy, which is used to produce ATP. C. Anabolic reactions break down complex organic compounds into simpler ones. D. Anabolic and catabolic reactions both build complex organic molecules from simpler ones; however, anabolic reactions use ATP, whereas catabolic reactions transfer energy to produceATP.

A. Anabolic reactions use ATP and small substrates as building blocks to synthesize larger molecules.

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle? A. Carbon dioxide (CO2) B. RuBP C. Sucrose (C12H22O11) D. Glucose (C6H12O6) E. G3P (C3H6O3)

A. Carbon dioxide (CO2)

What provides electrons for the light reactions? A. H2O B. Light C. The Calvin cycle D. CO2 E. O2

A. H2O

Which of the following is an acid produced by fermentation? A. Lactic acid and propionic acid B. Propionic acid C. Pyruvic acid D. Ethanol E. Lactic acid

A. Lactic acid and propionic acid

What is meant by substrate-level phosphorylation? A. Production of ATP by transferring phosphates directly from metabolic products to ADP B. Splitting of glucose into two pyruvic acid molecules C. Production of ATP using energy from a proton gradient D. Reduction of NAD+ to NADH

A. Production of ATP by transferring phosphates directly from metabolic products to ADP

One of the environmental changes that P. multocida encounters during infection is the limitation of nutrients and oxygen. One of the changes that P. multocida (a facultative anaerobe) makes in this environment is to switch to anaerobic metabolism. Predict which of the following is most likely to occur as a result of the switch from aerobic to anaerobic metabolism. A. The organisms will grow more slowly because they will produce less ATP compared to aerobic metabolism. B. During anaerobic metabolism, different electron carriers will be utilized; these will ultimately lead to less ATP production and slower growth of the organism. C. The amount of ATP produced will be relatively the same as aerobic metabolism because P. multocida will be able to respire anaerobically. D. Glycolysis, the Kreb's cycle, and electron transport will function as usual except that a different compound will be used as a final electron acceptor.

A. The organisms will grow more slowly because they will produce less ATP compared to aerobic metabolism.

What is the fate of metabolites during respiration? A. They are oxidized completely to carbon dioxide and water. B. They are reduced to from NADH and FADH2. C. They are rearranged to form GTP. D. They are oxidized completely to form pyruvic acid.

A. They are oxidized completely to carbon dioxide and water

Which of the following statements regarding metabolism is FALSE? A. Anabolic reactions are degradative. B. ATP is formed in catabolic reactions. C. ADP is formed in anabolic reactions. D. Heat may be released in both anabolic and catabolic reactions.

A. anabolic reactions are degradative

Which biochemical process is NOT used during glycolysis? A. beta-oxidation B. substrate-level phosphorylation C. oxidation-reduction D. carbohydrate catabolism E. enzymatic reactions

A. beta-oxidation

Why might some cells uncouple the electron transport chain? A. Cells can use the energy from the proton gradient for functions other than producing ATP, such as heat generation. B. Uncoupling proteins offset the effect of cyanide. C. Too much ATP is bad for the cell. D. A cell does not require ATP.

A. cells can use the energy from the proton gradient for functions other than producing ATP, such as heat generation

Which of the following uses CO2 for carbon and H2 for energy? A. chemoautotroph B. chemoheterotroph C. photoautotroph D. photoheterotroph

A. chemoautotroph

What occurs at the bridge step of the Krebs Cycle? A. Decarboxylation of pyruvic acid B. The formation of oxaloacetate C. The formation of succinyl CoA D. The production of GTP

A. decarboxylation of pyruvic acid

Why are enzymes important to biological systems? A. Enzymes decrease the amount of activation energy required for chemical reactions to occur. B. Enzymes increase the energy barrier required of chemical reactions. C. Enzymes are reusable. D. Enzymes prevent unwanted chemical by-products from forming.

A. enzymes decrease the amount of activation energy required for chemical reactions to occur

Why do eukaryotes generate only about 36 ATP per glucose in aerobic respiration but prokaryotes may generate about 38 ATP? A. eukaryotes must shuttle pyruvate across the mitochondrial membrane by active transport. B. eukaryotes do not completely oxidize glucose in their respiration reactions. C. eukaryotes have a less efficient electron transport system. D. prokaryotes possess an alternate to the Krebs cycle that generates more reduced electron.carriers. E. eukaryotes do not transport as much hydrogen across the mitochondrial membrane as prokaryotes do across the cytoplasmic membrane.

A. eukaryotes must shuttle pyruvate across the mitochondrial membrane by active transport.

Select the correct sequence of steps as energy is extracted from glucose during cellular respiration. A. glycolysis → acetyl CoA → citric acid cycle → electron transport chain B. citric acid cycle → electron transport chain → glycolysis → acetyl CoA C. electron transport chain → citric acid cycle → glycolysis → acetyl CoA D. glycolysis → citric acid cycle → acetyl CoA → electron transport chain E. acetyl CoA → citric acid cycle → electron transport chain → glycolysis

A. glycolysis → acetyl CoA → citric acid cycle → electron transport chain Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.

According to the animation, oxidative phosphorylation A. is a catabolic process. B. makes larger compounds from smaller ones. C. is an anabolic process. D. requires a net input of energy.

A. is a catabolic process

Which organism is NOT correctly matched to its energy source? A. photoautotroph - CO2 B. photoheterotroph - light C. chemoheterotroph - glucose D. chemoautotroph - NH3 E. chemoautotroph - Fe2+

A. photoautotroph - CO2

Glycolysis literally means A. sugar splitting. B. energy producing. C. sugar producing. D. Embden-Meyerhof.

A. sugar splitting

According to the animation, what does the electron transport chain do to the concentration of hydrogen ions (protons)? A. The concentration of protons is higher outside the membrane than inside. B. The concentration of protons is lower outside the membrane than inside. C. The concentration of protons inside the membrane is equal to the concentration outside of the membrane.

A. the concentration of protons is higher outside the membrane than inside

What is the main function of fermentation? A. To regenerate NAD+ for glycolysis. B. To produce sugars for ATP generation. C. To generate acetyl CoA for the Krebs cycle. D. To regenerate NADH for the electron transport chain.

A. to regenerate NAD+ for glycolysis

A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The bacteria are most likely A. using the peptides. B. oxidizing the glucose. C. not growing. D. fermenting the glucose.

A. using the peptides

Which of the following is used in photosynthesis by both plants and cyanobacteria? A. Water, sunlight, and carbon dioxide B. Water C. Carbon dioxide D. Sunlight

A. water, sunlight, and carbon dioxide

Which energy-rich molecule directly powers cell work?

ATP

Select all statements that correctly describe glycolysis. A. Each of the 10 steps in this pathway is catalyzed by the same enzyme. B. Glyceraldehyde 3-phosphate is oxidized, and NAD+ is reduced to NADH. C. Glucose is the original electron donor. D. More ATP is formed than is consumed in this process. E. Pyruvate is the electron acceptor. F. The 6-carbon skeleton of glucose is enzymatically split into two 3-carbon compounds. G. CO2 is produced during glycolysis. H. This process occurs in the mitochondria of eukaryotic cells.

B, C, D, & F

Select all statements that correctly describe the preparatory step and the Krebs cycle. A. CO2 serves as the electron acceptor. B. The equivalent of one ATP is made for each turn of the Krebs cycle. C. There are five oxidation-reduction reactions depicted. D. The oxaloacetic acid that accepts the acetyl group is regenerated, enabling the cyclic nature of this process. E. It takes two "turns" of the Krebs cycle to process the pyruvic acid molecules resulting from the glycolysis of one glucose molecule. F. Carbons from pyruvic acid end up as CO2. G. The potential energy in the pyruvate is transferred to coenzymes NAD+ and FAD. H. This process occurs in mitochondria in both eukaryotes and prokaryotes.

B, C, D, E, F, & G

Compare and contrast three metabolic pathways by choosing whether the statement applies to anaerobic respiration. Check all that apply. A. End products are CO2 and H2O B. Process includes glycolysis C. Process involves the Krebs cycle D. Between 2 and 38 ATP are produced per molecule of glucose input. E. Much or most of the ATP produced is produced by oxidative phosphorylation. F. A total of 38 ATP are produced per molecule of glucose input. G. End products may include lactic acid or ethanol. H. A total of 2 ATP are produced per molecule of glucose input. I. Process involves electron transport and chemiosmosis J. The coenzyme NAD+ plays an important role in the pathway. K. Can generate ATP in the absence of O2.

B, C, D, E, I, J & K

Compare and contrast three metabolic pathways by choosing whether the statement applies to fermentation. Check all that apply. A. End products are CO2 and H2O B. Process includes glycolysis C. Process involves the Krebs cycle D. Between 2 and 38 ATP are produced per molecule of glucose input. E. Much or most of the ATP produced is produced by oxidative phosphorylation. F. A total of 38 ATP are produced per molecule of glucose input. G. End products may include lactic acid or ethanol. H. A total of 2 ATP are produced per molecule of glucose input. I. Process involves electron transport and chemiosmosis J. The coenzyme NAD+ plays an important role in the pathway. K. Can generate ATP in the absence of O2.

B, G, H, J, & K

Which statements correspond to amphibolic pathways? 1. Anabolic and catabolic reactions are joined through common intermediate. 2. They are shared metabolic pathways. 3. Feedback inhibition can help regulate rates of reactions. 4. Both types of reactions are necessary but do not occur simultaneously. A. 2, 3, 4 B. 1, 2, 3 C. 1, 2, 3, 4 D. 1 only E. 2, 4

B. 1, 2, 3

Why is ATP required for glycolysis? A. ATP is used to convert PEP into pyruvic acid. B. ATP makes it easier to break apart glucose into two three-carbon molecules. C. ATP is used to reduce NAD+ to NADH. D. ATP is used to convert DHAP into G3P.

B. ATP makes it easier to break apart glucose into two three-carbon molecules.

What is the intermediate product formed by pyruvic acid during alcoholic fermentation? A. Lactic acid B. Acetaldehyde C. Carbon dioxide D. Ethanol E. Formic acid

B. Acetaldehyde

Which of the following is true of aerobic respiration compared to anaerobic respiration? A. Aerobic respiration uses oxygen as a final electron acceptor, whereas anaerobic respiration uses an organic molecule. B. Aerobic respiration uses oxygen as a final electron acceptor, whereas anaerobic respiration uses an inorganic molecule other than oxygen as the final electron acceptor. C. Aerobic respiration is less efficient than all forms of anaerobic respiration, producing less ATP and larger end-products. D. Aerobic respiration and anaerobic respiration both require oxygen as a final electron acceptor.

B. Aerobic respiration uses oxygen as a final electron acceptor, whereas anaerobic respiration uses an inorganic molecule other than oxygen as the final electron acceptor.

Where would you expect to find electron transport chains in a prokaryote? A. Free-floating in the cytoplasm B. Along the plasma membrane C. Along the inner mitochondrial membrane D. Along the cell wall E. Along the outer mitochondrial membrane

B. Along the plasma membrane

Which of the following statements regarding competitive inhibitors is true? A. The inhibitor will destroy the enzyme. B. Competitive inhibitors decrease the rate of enzyme activity. C. The inhibitor will destroy the substrate. D. The inhibitor will degrade the substrate.

B. Competitive inhibitors decrease the rate of enzyme activity

How does cyanide poisoning result in the decrease of ATP production? A. Cyanide permanently binds to oxygen, preventing its use as the final electron acceptor. B. Cyanide permanently reduces cytochrome a3, preventing other components to change into the oxidized state. This causes the proton gradient to break down, stopping ATP synthesis. C. Cyanide uncouples the proton gradient from the process of ATP synthesis. D. Cyanide permanently oxidizes cytochrome a3, preventing other components to change into the reduced state. This causes the proton gradient to break down, stopping ATP synthesis.

B. Cyanide permanently reduces cytochrome a3, preventing other components to change into the oxidized state. This causes the proton gradient to break down, stopping ATP synthesis.

Which of the following statements about glycolysis is true? A. Glycolysis is the main source of NADH in the cell. B. Glycolysis is also called the Embden-Meyerhof pathway. C. Glycolysis produces glucose. D. All cells perform glycolysis.

B. Glycolysis is also called the Embden-Meyerhof pathway

In which organism would you likely find a chlorosome? A. Cyanobacteria B. Green sulfur bacteria C. Purple sulfur bacteria D. Purple nonsulfur bacteria E. Algae

B. Green sulfur bacteria

What is the role of pyruvic acid in fermentation? A. It becomes the final electron acceptor for the electron transport chain in the absence of oxygen. B. It takes the electrons from NADH, oxidizing it back into NAD+. C. It is the organic acid end-product of fermentation. D. It provides the protons to be used in the electron transport chain.

B. It takes the electrons from NADH, oxidizing it back into NAD+

Which compound is being reduced in the reaction shown in the figure? A. NADH and isocitric acid B. NAD+ C. NADH D. isocitric acid and α-ketoglutaric acid E. α-ketoglutaric acid and NAD+

B. NAD+

Glycolysis produces energy in which form? A. ATP B. NADH and ATP C. NADH, ATP, and pyruvic acid D. Pyruvic acid E. NADH

B. NADH and ATP

Which of the following statements regarding the glycolysis pathway is FALSE? A. Two molecules of water are generated. B. One molecule of ATP is expended. C. Two pyruvate molecules are generated. D. Two NADH molecules are generated. E. Four ATP molecules are generated via substrate-level phosphorylation.

B. One molecule of ATP is expended.

Which of the following is needed as a reactant for the first step of the citric acid cycle? A. Citric acid B. Oxaloacetic acid C. Succinyl CoA D. Malic acid

B. Oxaloacetic acid

What is the key difference between photoheterotrophs and photoautotrophs? A. Photoheterotrophs produce oxygen as a by-product; photoautotrophs do not. B. Photoheterotrophs use organic compounds as their carbon source; photoautotrophs use carbon dioxide as their carbon source. C. Photoautotrophs only use bacteriochlorophyll; photoheterotrophs only use chlorophyll a. D. Photoheterotrophs use hydrogen sulfide for reducing power; photoautotrophs do not.

B. Photoheterotrophs use organic compounds as their carbon source; photoautotrophs use carbon dioxide as their carbon source.

How does the proton gradient help ATP synthase to make ATP? A. Protons move from inside the membrane to outside the membrane. B. Protons move from outside the membrane to inside the membrane. C. Protons are not involved with this step; only electrons are. D. Protons move along the membrane.

B. Protons move from outside the membrane to inside the membrane

Which statement describes glycolysis? A. This process produces some ATP and carbon dioxide in the mitochondrion. B. This process splits glucose in half and produces 2 ATPs for each glucose. C. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. D. This process converts pyruvic acid to acetyl CoA. E. This process joins 2 pyruvic acid molecules into a molecule of glucose.

B. This process splits glucose in half and produces 2 ATPs for each glucose.

How many net ATPs can be made from one molecule of glucose in glycolysis? A. Four B. Two C. Six D. One

B. Two

What is one difference between ubiquinones and cytochromes? A. Ubiquinones can only be reduced; cytochromes can only be oxidized. B. Ubiquinones are not made of protein; cytochromes are. C. Ubiquinones can only be oxidized; cytochromes can only be reduced. D. Ubiquinones cannot carry electrons; cytochromes can.

B. Ubiquinones are not made of protein; cytochromes are

A reaction that involves the transfer of electrons from one molecule to another is referred to as A. a reduction reaction. B. a redox reaction. C. an oxidation reaction.

B. a redox reaction

Researchers are developing a ribozyme that cleaves the HIV genome. This pharmaceutical agent could be described as A. a genetic transposable element. B. an RNA molecule capable of catalysis. C. a competitive inhibitor for reverse transcriptase. D. a hydrolase. E. a protease inhibitor.

B. an RNA molecule capable of catalysis

What is the function of GTP? A. An electron carrier B. An energy carrier C. An oxidizer to produce CO2 D. A scaffolding for carbon atoms

B. an energy carrier

The process of generating ATP using a proton gradient is referred to as A. water damming. B. chemiosmosis. C. the electron transport chain.

B. chemiosmosis

In which of the following organelles does photosynthesis take place? A. Nucleus B. Chloroplast C. Ribosome D. Mitochondrion E. Central vacuole

B. chloroplast

What molecule is used to capture light energy? A. NADPH B. Chlorophyll C. Carbon dioxide D. Water E. ATP

B. chlorphyll

Increasing the temperature of a reaction will do all of the following EXCEPT A. increase the reaction rate. B. increase the activation energy. C. increase the number of molecules attaining activation energy. D. increase kinetic energy of the molecules. E. increase the number of molecular collisions.

B. increase the activation energy

The use of amino acids to make proteins A. is an example of catabolism. B. is an example of anabolism. C. involves the production of ATP. D. is a completely efficient reaction.

B. is an example of anabolism

Which of the following statements about anaerobic respiration is FALSE? A. It requires cytochrome. B. It involves the reduction of an organic final electron acceptor. C. It yields lower amounts of ATP when compared to aerobic respiration. D. It generates ATP. E. The complete Krebs cycle is utilized.

B. it involves the reduction of an organic final electron acceptor

Which of the following statements about fermentation is true? A. It provides additional protons to allow the electron transport chain to continue. B. It is an alternative way to return electron carriers to their oxidized state. C. It allows the electron transport chain to continue in the absence of oxygen. D. It is an alternative way for a cell to produce oxygen.

B. it is an alternative way to return electron carriers to their oxidized state

In the generation of ATP, energy is released when electrons are passed to a series of electron acceptors and finally to oxygen or another inorganic compound. What is this process called? A. photophosphorylation B. oxidative phosphorylation C. substrate-level phosphorylation D. catabolism

B. oxidative phosphorylation

Which of the following statements regarding redox reactions is true? A. Redox reactions must either be oxidizing reactions or reducing reactions. B. Redox reactions involve an oxidation reaction coupled with a reduction reaction. C. Redox reactions are only seen in the electron transport chain. D. No metabolic reactions are redox reactions.

B. redox reactions involve an oxidation reaction coupled with a reduction reaction

During an oxidation reaction, A. the donor molecule gains an electron and becomes oxidized. B. the donor molecule loses an electron and becomes oxidized. C. the acceptor molecule gains an electron and becomes oxidized. D. the acceptor molecule loses an electron and becomes oxidized.

B. the donor molecule loses an electron and becomes oxidized

What is the driving force of energy production in steps 6 and 7? A. The energy potential of a proton gradient B. The oxidation of three-carbon compounds C. The reduction of three-carbon compounds D. The reduction of NAD+ to NADH

B. the oxidation of three-carbon compounds

The advantage of the pentose phosphate pathway is that it produces all of the following EXCEPT A. precursors for nucleic acids. B. three ATPs. C. precursors for the synthesis of amino acids. D. precursors for the synthesis of glucose. E. NADPH.

B. three ATPs

What is the role of light energy in photosynthesis? A. To make glucose in the Calvin-Benson cycle B. To produce a proton gradient to make ATP C. To produce carbon dioxide D. To manufacture chloroplasts

B. to produce a proton gradient to make ATP

Which of the following situations does not result in a breakdown of the proton gradient? A. Oxygen deprivation B. Uncoupling proteins C. Cyanide poisoning

B. uncoupling proteins

According to the animation, what does oxygen get reduced to at the end of the electron transport chain? A. ATP B. Water C. NADH D. Protons E. Electrons

B. water

What is the correct general equation for cellular respiration? A. C6H12O6 + 6CO2 → 6O2 + 6H2O + ATP energy B. 6CO2 + 6H2O + ATP energy → C6H12O6 + 6O2 C. C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP energy D. C6H12O6 + 6H2O → 6CO2 + 6O2 + ATP energy E. 6O2 + 6H2O + ATP energy → C6H12O6 + 6CO2

C. C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP energy

Where does the energy required for anabolic reactions come from? A. Heat B. Unused energy from metabolism C. Catabolic reactions

C. Catabolic reactions

What enables competitive inhibitors to bind to a specific enzyme? A. Competitive inhibitors have unique sugars that are attracted to the enzyme. B. Competitive inhibitors cover the entire surface of an enzyme. C. Competitive inhibitors have structures that resemble the enzyme's substrate. D. Competitive inhibitors form unique covalent bonds with enzyme structures.

C. Competitive inhibitors have structures that resemble the enzyme's structures

Why does FADH2 yield less ATP than NADH? A. FADH2 electrons ultimately do not go to oxygen. B. Electrons from FADH2 cannot pump hydrogen ions out of the cell. C. FADH2 electrons enter the electron transport chain at a lower energy level. D. FADH2 binds directly to the ATP synthase enzyme.

C. FADH2 electrons enter the electron transport chain at a lower energy level

Which of the following is NOT a sign or symptom of irritable bowel syndrome (IBS)? A. Constipation B. Cramping C. Fever D. Abdominal pain E. Diarrhea

C. Fever

Based on the animation, how many electron carriers are reduced in the Krebs cycle only? A. Five B. Six C. Four D. Three

C. Four

At the doctor's office, the doctor drains the abscess and takes a sample for culturing. She also prescribes some broad-spectrum antibiotics to treat the obvious infection. A couple days later, the doctor tells Sam that his wound contained a number of bacteria including Pasteurella multocida. When the dog bit Sam's arm P. multocida entered the wound and started to establish an infection. In order to do so, the bacteria have to grow, which requires energy. One of the most common energy sources used by bacteria is glucose. Why is glucose such a good source of energy for bacteria? A. Glucose contains six oxygen atoms, which can be used for oxidative phosphorylation and the generation of many ATP molecules. B. Glucose contains six carbon atoms, which can be quickly incorporated into organic cellular constituents needed for growth. C. Glucose is a highly reduced compound, containing many carbon-hydrogen bonds and a lot of potential energy. D. Glucose is a highly oxidized compound, containing many carbon-hydrogen bonds and a lot of potential energy.

C. Glucose is a highly reduced compound, containing many carbon-hydrogen bonds and a lot of potential energy.

Which of the following gases is or are produced during the breakdown of cysteine and methionine and is responsible for foul-smelling flatulence? A. Pyruvate B. O2 C. H2S D. H2O

C. H2S

Iron is considered an essential element for many bacteria. Based on the animation, how would lack of iron affect energy production of a bacterium? A. Lack of iron would not have any affect on this system. B. Lack of iron would mean that most of the oxygen could be reduced to form water, improving energy yields. C. Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.

C. Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields

A urease test is used to identify Mycobacterium tuberculosis because A. urease is a sign of tuberculosis. B. M. bovis can cause tuberculosis. C. M. tuberculosis produces urease. D. urea accumulates during tuberculosis. E. some bacteria reduce nitrate ion.

C. M. tuberculosis produces urease.

Which of the following can be used as a final electron acceptor for aerobic respiration? A. Nitrate ion B. Carbonate ion C. Molecular oxygen D. Sulfate ion E. Nitrate ion, sulfate ion and carbonate ion can all be used as a final electron acceptor.

C. Molecular oxygen

Which of the following statements regarding the Entner-Doudoroff pathway is TRUE? A. It involves glycolysis. B. It involves the pentose phosphate pathway. C. NADH and ATP are generated. D. ATP is generated. E. NADH is generated.

C. NADH and ATP are generated

According to the animation, which compounds provide electrons to the system? A. FADH2 B. Water C. NADH and FADH2 D. NADH E. Oxygen

C. NADH and FADH2

If high amounts of sulfanilamide are in the presence of an enzyme whose substrate is PABA, what outcome is expected? A. The substrate will destroy the inhibitor. B. Sulfanilamide products will be in higher concentration. C. PABA will not be catalyzed. D. PABA products will increase in concentration.

C. PABA will not be catalyzed

Which of the following types of organisms uses hydrogen sulfide for reducing power? A. Green nonsulfur bacteria B. Algae C. Purple sulfur bacteria D. Purple nonsulfur bacteria E. Cyanobacteria

C. Purple sulfur bacteria

Where does the energy come from to power the formation of GTP? A. Water B. NADH C. Succinyl CoA D. ATP

C. Succinyl CoA

Why does lack of oxygen result in the halt of ATP synthesis? A. It causes one of the cytochromes in the electron transport chain to be permanently stuck in the reduced state. B. Oxygen prevents uncoupling of the electron transport chain. C. The chain shuts down and can no longer pump hydrogen ions across the membrane, and the proton gradient cannot be maintained.

C. The chain shuts down and can no longer pump hydrogen ions across the membrane, and the proton gradient cannot be maintained.

The P. multocida that are growing within Sam's abscess are breaking glucose down via glycolysis in order to obtain energy. This process occurs via a series of enzymatic reactions. During a chemical reaction, an enzyme functions as a biological catalyst and lowers the activation energy. How does an enzyme lower the activation energy of a reaction? A. As the enzyme is utilized, heat is released causing an increase in the reaction rate and a subsequent lowering in the energy of activation. B. The breakdown of the enzyme provides energy to the reactants allowing them to reach activation energy more quickly. C. The enzyme increases the effectiveness of reactant collisions thereby increasing the number of reactant molecules that reach activation energy. D. The enzyme increases the potential energy available to the reactants, thereby decreasing the activation energy that must be reached.

C. The enzyme increases the effectiveness of reactant collisions thereby increasing the number of reactant molecules that reach activation energy.

Which of the following best describes the role of the gut microbiome in human digestion? A. The gut microbiome does not contribute to human digestion. B. The gut microbiome reduces the production of intestinal gases. C. The gut microbiome breaks down dietary compounds that human metabolic enzymes cannot break down. D. The gut microbiome produces ATP for human cells.

C. The gut microbiome breaks down dietary compounds that human metabolic enzymes cannot break down.

How does a competitive inhibitor slow enzyme catalysis? A. They degrade the substrate. B. They bind to the substrate. C. They compete with the substrate for the enzyme's active site. D. They produce products toxic to the enzymes.

C. They compete with the substrate for the enzyme's active site

What connects the two photosystems in the light reactions? A. The Calvin cycle B. A thylakoid C. An electron transport chain D. A chain of glucose molecules E. Chlorophyll

C. an electron transport chain

The reactions involved in producing larger compounds from smaller compounds is called A. metabolism. B. catabolism. C. anabolism.

C. anabolism

Which type of metabolic diversity contains most pathogens? A. chemoautotroph B. photoheterotroph C. chemoheterotroph D. photoautotroph

C. chemoheterotroph

Which of the following compounds is NOT an enzyme? A. β-galactosidase B. sucrase C. coenzyme A D. dehydrogenase E. cellulase

C. coenzyme A

Why do all enzymatic reactions need activation energy? A. Energy is needed for the enzyme to find its substrate. B. Energy is required by an enzyme so that it can be reused. C. Energy is required to disrupt a substrate's stable electron configuration. D. Energy allows only the substrate to bind.

C. energy is required to disrupt a substrate's stable electron configuration

The Pentose Phosphate Pathway... A. is a part of photosynthesis. B. is another name for fermentation. C. is an example of anabolism. D. is an example of catabolism.

C. is an example of anabolism

In metabolism, energy that is not used A. is stored in the form of ATP. B. is used to break down large molecules into smaller ones. C. is given off as heat. D. is used to build up large compounds from smaller ones.

C. is given off as heat

What is the fate of the NAD+ newly regenerated by fermentation? A. It is converted into an organic acid. B. It is oxidized into carbon dioxide. C. It returns to glycolysis to pick up more electrons. D. It is converted into ethanol.

C. it returns to glycolysis to pick up more electrons

Gallionella bacteria can get energy from the reaction Fe2+ → Fe3+. This reaction is an example of A. the Calvin-Benson cycle. B. fermentation. C. oxidation. D. photophosphorylation. E. reduction.

C. oxidation

You have just started brewing beer at home, and your first batch is now ready. You used the yeast Saccharomyces cerevisia, which can perform both aerobic cellular respiration and fermentation. When you test the beer, you determine that the alcohol content is almost zero. What could have been present in the fermentation reaction apparatus that caused this problem? A. carbon dioxide B. pyruvic acid C. oxygen D. glucose

C. oxygen

How is ATP generated in the reaction shown in the figure? A. photophosphorylation B. fermentation C. substrate-level phosphorylation D. glycolysis E. oxidative phosphorylation

C. substrate-level phosphorylation

Why is reduction the term used to describe the gain of an electron? A. The number of molecules in the reaction decreases. B. The amount of energy in the molecule decreases. C. The electron acceptor's net charge decreases. D. The electron acceptor gets smaller.

C. the electron acceptor's net charge decreases

How does a noncompetitive inhibitor reduce an enzyme's activity? A. The inhibitor inactivates the enzyme. B. The inhibitor degrades the enzyme. C. The inhibitor binds to the enzyme in a location other than the active site, changing the shape of the active site. D. The inhibitor degrades the enzyme's normal substrate.

C. the inhibitor binds to the enzyme in a location other than the active site, changing the shape of the active site

Which of the following is a trait unique to photosynthetic eukaryotes? A. The presence of chlorophyll a B. Using water for reducing power C. The presence of chloroplasts D. Living in aerobic environments E. The presence of thylakoid membranes

C. the presence of chloroplasts

Which step(s) of the Krebs cycle does (do) not produce any usable energy? A. The sixth step B. The first and eighth steps C. The second and seventh steps D. The fifth step E. The third step

C. the second and seventh steps

Which step involves the release of carbon dioxide? A. The seventh step B. The first and eighth steps C. The third and fourth steps D. The second step

C. the third and fourth steps

How many molecules of ATP can be generated from one molecule of NADH? A. Four B. Two C. Three D. One

C. three

The light reactions take place in the _________ and the Calvin cycle takes place in the _________. A. inner membrane; outer membrane B. mitochondria; chloroplasts C. thylakoids; stroma D. chloroplasts; mitochondria E. stroma; thylakoids

C. thylakoids; stroma

What is the net production of ATP in glycolysis? A. Six ATP B. Four ATP C. Two ATP D. Eight ATP

C. two ATP

Sort the statements into the appropriate bin depending on whether they correctly or incorrectly describe some aspect of the electron transport chain and chemiosmosis.

Correct statements:The final electron acceptor is O2.A chemical that inactivates cytochrome c so that it can't pass electrons on to cytochrom a would block electron transport and ATP synthesis.The pH of the intermembrane space in the mitochondria would be lower than the pH of the mitochondrial matrix in an actively metabolizing cell.A toxin that causes a leak to form in the inner mitochondrial membrane such that protons could bypass the ATP synthase would prevent oxidative phosphorylation.Incorrect statements:Electrons moving from the FMN to Q to cytochrome b are gaining energy.ATP serves as an electron carrier in the electron transport chain.A toxin that causes a leak to form in the inner mitochondrial membrane such that protons could bypass the ATP synthase would disrupt the flow of electrons to O2.The electrons carried by FADH2 have more potential energy than those carried by NADH.

Refer to the figure. In aerobic respiration, where is water formed? A B C D E

D

Fatty acids are oxidized in A. the Entner-Doudoroff pathway. B. the pentose phosphate pathway. C. glycolysis. D. the Krebs cycle. E. the electron transport chain.

D. the Krebs cycle

Which of the following equations represents photosynthesis? A. 6CO2 + 6O2 → C6H12O6 + 6H2O B. C6H12O6 + 6O2 → 6CO2 + 6H2O C. 6H2O + 6O2 → C6H12O6 + 6CO2 D. 6CO2 + 6H2O → C6H12O6 + 6O2 E. C6H12O6 + 6CO2 → 6O2 + 6H2O

D. 6CO2 + 6H2O → C6H12O6 + 6O2

Which of the following is the best definition of oxidative phosphorylation? A. ATP is directly transferred from a substrate to ADP. B. Electrons are passed through a series of carriers to an organic compound. C. Electrons are passed through a series of carriers to O2. D. A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP.

D. A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP.

What two molecules are produced by the light reactions and used to power the Calvin cycle? A. C6H12O6 and O2 B. CO2 and O2 C. G3P and H2O D. ATP and NADPH E. C6H12O6 and RuBP

D. ATP and NADPH

Which step is the step for which glycolysis is named? A. First B. Second C. Third D. Fourth E. Fifth F. Sixth

D. Fourth

How is nevirapine used to treat HIV infections? A. It decreases the virus's ability to find host cells. B. It binds to the active site of HIV reverse transcriptase, decreasing that enzyme's activity. C. It increases the immune system's ability to detect the virus. D. It alters the active site of reverse transcriptase, decreasing that enzyme's activity.

D. It alters the active site of reverse transcriptase, decreasing that enzyme's activity

What transports electrons from the light reactions to the Calvin cycle? A. FADH2 B. NADH C. Chlorophyll D. NADPH E. An electron transport chain

D. NADPH

What carbon molecules remain at the end of glycolysis? A. Dihydroxyacetone phosphate (DHAP) B. Glyceraldehyde 3-phosphate (G3P) C. Glucose D. Pyruvic acid

D. Pyruvic acid

A key feature of cellular respiration is the removal of electrons from fuel molecules (oxidation) and the ultimate acceptance of these electrons by a low-energy electron acceptor. The process involves the use of electron carriers, NAD+ and FAD, which play crucial roles in multiple steps of the metabolic pathways. The overall equation for cell respiration is shown below. Why do NAD+ and FAD NOT appear in the overall equation? C6H12O6+6O2+38ADP+38Pi→6CO2+6H2O+38ATP A. Glucose and CO2 are the electron carriers in this pathway. B. This pathway doesn't use electron carriers such as NAD+ and FAD and uses only the electron transport chain. C. ADP is the electron carrier in this pathway and picks up electrons to form ATP. D. The NAD+ and FAD are initially reduced then oxidized to their original state, so they do not appear in the net equation.

D. The NAD+ and FAD are initially reduced then oxidized to their original state, so they do not appear in the net equation.

Microbes are often identified using biochemical tests that detect specific enzymes of metabolic pathways. E. coli typically ferments lactose, whereas Shigella does not. If a pure culture of each bacterium was placed in a tube containing lactose as the only food source, and a chemical indicator changed color after a pH change, what would the tubes look like after the bacteria were incubated? A. Neither tube will show any change. B. Both tubes would show the evidence of lactose fermentation by turning acidic and changing the pH indicator. C. Both tubes would show the evidence of lactose fermentation by turning alkaline. D. The tube with E. coli would show a pH change, and the Shigella tube would show no change.

D. The tube with E. coli would show a pH change, and the Shigella tube would show no change.

Which statement describes the citric acid cycle? A. This process converts pyruvic acid to acetyl CoA. B. This process joins 2 pyruvic acid molecules into a molecule of glucose. C. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. D. This process produces some ATP and carbon dioxide in the mitochondrion. E. This process splits glucose in half and produces 2 ATPs for each glucose.

D. This process produces some ATP and carbon dioxide in the mitochondrion.

According to the animation, the reactions that occur between glucose and pyruvic acid A. are neither catabolic nor anabolic. B. are only catabolic. C. are only anabolic. D. can either be anabolic or catabolic

D. can either be anabolic or catabolic

What is meant by the statement "Enzymes are biological catalysts"? A. Enzymes produce products useful for biology. B. Enzymes produce biological organisms. C. Enzymes are products of biological systems. D. Enzymes speed up the chemical reactions in living cells.

D. enzymes speed up the chemical reactions in living cells

What is the fate of pyruvic acid in an organism that uses aerobic respiration? A. It is reduced to lactic acid. B. It reacts with oxaloacetate to form citrate. C. It is catabolized in glycolysis. D. It is converted into acetyl CoA. E. It is oxidized in the electron transport chain.

D. it is converted into acetyl CoA

Lipases break down... A. carbohydrates. B. proteins. C. nucleic acids. D. lipids.

D. lipids

What would be the likely outcome if you increased the concentration of substrate for an enzyme in the presence of a noncompetitive inhibitor? A. A decrease in the amount of inhibitor would be observed. B. A decrease in the concentration of enzyme would be observed. C. You would begin to see an increase in the enzyme's rate of activity. D. No change in enzyme activity would be observed.

D. no change in enzyme activity would be observed

If a cell is starved for ATP, which of the following pathways would most likely be shut down? A. glycolysis B. Krebs cycle and glycolysis C. Krebs cycle D. pentose phosphate pathway

D. pentose phosphate pathway

Which of the following is a bacterium that performs oxygenic photosynthesis? A. Purple nonsulfur bacteria B. Green sulfur bacteria C. Purple sulfur bacteria D. Green nonsulfur bacteria E. Cyanobacteria

E. Cyanobacteria

Which statement describes the electron transport chain? A. This process produces some ATP and carbon dioxide in the mitochondrion. B. This process joins 2 pyruvic acid molecules into a molecule of glucose. C. This process converts pyruvic acid to acetyl CoA. D. This process splits glucose in half and produces 2 ATPs for each glucose. E. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.

E. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.

Which of the following processes takes place in the cytosol of a eukaryotic cell? A. citric acid cycle B. electron transport chain C. ATP production by ATP synthase D. acetyl CoA formation E. glycolysis

E. glycolysis

Microorganisms that catabolize sugars into ethanol and hydrogen gas would most likely be categorized as A. anaerobic respirers. B. aerobic respirers. C. alcohol fermenters. D. homolactic fermenters. E. heterolactic fermenters.

E. heterolactic fermenters

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain? A. Golgi apparatus B. lysosome C. chloroplast D. nucleus E. mitochondrion

E. mitochondrion

In the figure, the path labeled "2" is the flow of A. electrons B. water C. energy D. glucose E. protons

E. protons

Which of the following is the best definition of fermentation? A. the partial reduction of glucose to pyruvic acid B. the complete catabolism of glucose to CO2 and H2O C. the production of energy by oxidative-level phosphorylation D. the production of energy by both substrate and oxidative phosphorylation E. the partial oxidation of glucose with organic molecules serving as electron acceptors

E. the partial oxidation of glucose with organic molecules serving as electron acceptors

The image below shows three different oxidation-reduction equations. Sort each of the lettered items on the image into the proper bin.

Electron donors : a, e , i Electron acceptors : b, f, j Oxidized product: c, g , k Reduced product: h, d, l

Arrange the components of the electron transport chain in order from least electronegative to most electronegative thereby indicating the path of electrons through the electron transport chain. Cytochromec NADH dehydrogenase cytochrome oxidase complex O2 Coenzyme Q Cytochromeb-c1 complex

NADH dehydrogenase > Coenzyme Q > Cytochromeb-c1 complex > Cytochromec > cytochrome oxidase complex > O2

True or False: Catabolic reactions are generally degradative and hydrolytic

True