Chp 6 - Metabolism - Questions/Answers

Please choose the answer that best completes the blanks of this sentence in the correct order. The three basic catabolic pathways are ________ respiration (oxygen is the final electron acceptor), _________ respiration (nonoxygen electron acceptors), and __________ (organic molecules as final electron acceptors). a. anaerobic; aerobic; fermentation b. aerobic; fermentative; anaerobic metabolism c. aerobic; anaerobic; fermentation

c. aerobic; anaerobic; fermentation

The NADH involved in the electron transport chain is made: a. by reduction reactions in the Krebs Cycle b. By oxidation in the krebs cycle only c. by oxidation reactions in glycolysis and the Krebs cycle d. by reduction reactions in glycolysis and the Krebs cycle

c. by oxidation reactions in glycolysis and the Krebs cycle

Synthesis of ATP via a proton gradient is called a. glycolysis. b. Krebs cycle. c. chemiosmosis. d. substrate-level e.phosphorylation. f. cyclophosphorylation.

c. chemiosmosis.

Please choose the answer that best completes the blanks of this sentence in the correct order. _________ inhibition of an enzyme occurs when the inhibitor mimics the substrate and occupies the active site of the enzyme, whereas ___________ inhibition occurs when an inhibitor binds to a regulatory site on the enzyme that is separate and distinct from the active site. a. noncompetitive; competitive b. allosteric; competitive c. competitive; noncompetitive

c. competitive; noncompetitive

The two 3-carbon molecules which glucose is split into are converted through a series of steps into the final 3-carbon molecule. During these later steps, _____ molecule(s) of ATP are made. a. one b. two c. four

c. four

The Krebs cycle occurs after _________ a. the electron transport chain b. the Calvin Cycle c. glycolysis d. fermentation

c. glycolysis

Which of the following binds to the active site of an enzyme? a. water b. product c. substrate d. any other enzyme e. none of the above

c. substrate

Oxygen acts as a. a carrier of electrons, passing electrons down the chain. b. a reducing agent. c. the terminal electron acceptor. d. a coenzyme.

c. the terminal electron acceptor

Coenzymes Q: a. transfers protons from outside the membrane to inside the membrane b. is the last step in the electron transport chain c. transfers protons from inside the membrane to outside the membrane d. removes protons from water

c. transfers protons from inside the membrane to outside the membrane

The NET production of ATP upon the completion of the series of glycolytic reactions is ______ molecule(s) of ATP a. four b. six c. two d. one

c. two

Where does the Krebs cycle take place in bacteria? a. Nucleus b. Mitochondria c. Cell membrane d. Cytoplasm

d. Cytoplasm

Which of the following correctly represents the mechanism of enzyme function, where S is "substrate" and E is "enzyme" and P is "product"? a. S + P -> E-P -> E + P b. E + P -> E-P -> E-S -> E + S c. E + P -> E-S -> E-P -> E + P d. E + S -> E-S -> E-P -> E + P e. E + S -> E-P -> E-S -> E + S

d. E + S -> E-S -> E-P -> E + P

Glycolysis makes products that feed into: a. fermentation b. all of the above c. electron transport d. Krebs Cycle

d. Krebs cycle

Hydrogens are transported from other reactions to the electron transport chain by: a. NADH and coenzyme A b. NADH and coenzyme Q c. Cytochrome c and coenzyme Q d. NADH and FADH

d. NADH and FADH

Which of the following is NOT a catabolic process? a. Hydrolysis of ATP b. Glycolysis c. Fermentation d. Photosynthesis

d. Photosynthesis

The energy released during the reactions of glycolysis is used to form: a. glycogen b. glycerol c. guanine triphosphate d. adenosine triphosphate

d. adenosine triphosphate

Protons received from NADH a. act as coenzymes. b. are passed along the electron transport chain along with the electrons. c. are the terminal electron acceptors. d. are pumped outside the cell.

d. are pumped outside the cell

A product or products of glycolysis is/are a. ATP b. pyruvate c. CO2 d. both a and b

d. both a and b

Early in glycolysis, two phosphates are added to the glucose molecule. These phosphates come from: a. conversion of NADH b. hydrolysis of KH2PO4 c. transfer from phospholipids d. breaking down ATP

d. breaking down ATP

In eukaryotes, glycolysis takes place in the ____. a. plasma membrane b. endoplasmic reticulum c. mitochondria d. cytoplasm

d. cytoplasm

The final acceptor for electrons and hydrogens in aerobic respiration is: a. SO42- b. organic compounds c. pyruvic acid d. free oxygen e. H20

d. free oxygen

In bacteria, the electron transport chain is located: a. in the glycocalyx b. in mitochondria c. in cristae d. in the plasma membrane

d. in the plasma membrane

An enzyme a. becomes part of the final products b. is nonspecific c. is consumed by the reaction d. is heat and pH labile

d. is heat and pH labile

Where does carbon dioxide go when it is released during reactions of the Krebs cycle? a. It donates electrons to the electron transport chain for ATP Production b. it enters a fermentation pathway to form ATP c. It catalyzes a glycolytic reaction d. it diffuses out of the cell

d. it diffuses out of the cell

Cells prefer to use carbohydrates as energy sources because: a. their internal bonds are so easy to cleave b. they contain the greatest amount of energy per unit c. the waste products of their breakdown d. they are such good donors of hydrogen and electrons

d. they are such good donors of hydrogen and electrons

For one turn of the Krebs cycle, how many NADH are produced? a. six b. depends on if the process is aerobic or anaerobic c. two d. three

d. three

For each glucose molecule that enters glycolysis, how many times does the Krebs cycle turn? a. six b. three c. one d. two

d. two

Which of the following is the enzyme used to synthesize ATP? a. ATP phosphodiesterase b. ATP hydrolase c. ATP kinase d. ATP phosphorylase e. none of the above

e. none of the above

Which of these molecules cannot be broken down to release energy? a. sugar b. starch c. fat d. protein e. none of the above (all of these can release energy)

e. none of the above (all of these can release energy)

Proton pumps are protein complexes that a. break down water into hydrogen and oxygen. b. synthesize water from hydrogen and oxygen. c. pump protons and electrons through the cell membrane. d. pump protons from the exterior of the cell to the interior. e. pump protons from the interior of the cell to the exterior.

e. pump protons from the interior of the cell to the exterior.

The two 3-carbon molecules that glucose is split into during glycolysis are converted through a series of steps ending in what 3-carbon molecule? a. Fructose 1.6 diphosphate b. Diphosphglyceric acid c. Acetyl CoA d. citric acid e. Pyruvate

e. pyruvate

A hydrogen atom consists of a proton and a pair of electrons. True False

False

An enzyme can only bind one reactant at a time. True False

False

An enzyme speeds up a chemical reaction in the cell, but can only be used once. True False

False

In prokaryotes and eukaryotes, the Krebs cycle takes place in the mitochondria.T/F

False

The Krebs cycle is part of fermentation, as well as cellular respiration. T/F

False

The membrane is permeable to protons. True False

False

Which of the following statements best describes why a rising serum lactate level may be of concern for this patient? a. Fermentation fatigues body cells b. Fermentation is a limited supply of energy for body cells c. Fermentation is a poor supply of energy for body cells d. Fermentation is harmful for body cells

b. Fermentation is a limited supply of energy for body cells

Which of the following processes is not a part of fermentation? a. Electron tranport system b. Krebs cycle and electron transport system c. Glycolysis d. Krebs cycle

b. Krebs cycle and electron transport system

When protons are pumped outside the cell membrane a. water is made. b. a proton motive force is created. c. NADH gets reduced. d. electrons are lost.

b. a proton motive force is created.

The electron transport chain is part of ______. a. fermentation b. aerobic respiration c. glycolysis d. pyruvate oxidation

b. aerobic respiration

Please choose the answer that best completes the blanks of this sentence in the correct order. Both aerobic respiration and anaerobic respiration utilize glycolysis, Krebs cycle, and an electron transport system, but in ________ respiration, O2 is the final electron acceptor at the end of the electron transport system, whereas in _________, an inorganic molecule other than O2 is the final electron acceptor. a. aerobic; fermentative b. aerobic; anaerobic c. anaerobic; aerobic d. fermentative; anaerobic

b. aerobic; anaerobic

Please choose the answer that best completes the blanks of this sentence in the correct order. All of the chemical reactions that occur within a cell are collectively referred to as metabolism. This includes _________, which are those reactions that use energy and synthesize building blocks and macromolecules, and __________, which are the cellular reactions that break larger molecules into smaller molecules and release energy. a. catabolism; anabolism b. anabolism; catabolism c. anabolism; amphibolism d. amphibolism; catabolism

b. anabolism; catabolism

When the product of a metabolic pathway accumulates, it may be able to slow down or turn off the pathway by inhibiting the activity of an enzyme that catalyzes an early step in the pathway. This is referred to as _______ inhibition. a. competitive b. feedback c. redox d. amphibolic

b. feedback

Glycolysis is the breakdown of: a. starch b. glucose c. glycogen d. fatty acids

b. glucose

Energy is carried from catabolic to anabolic reactions in the form of a. ADP b. high-energy ATP bonds c. coenzymes d. inorganic phosphate

b. high-energy ATP bonds

Hydrogen consists of: a. two protons and one electrons b. one proton and one electron c. one protons and two electrons d. two protons and two electrons

b. one proton and one electron

The main purpose of cellular respiration is to _____. a. produce water b. produce energy c. produce carbon dioxide d. produce glucose

b. produce energy

Enzymes are a. lipids. b. proteins. c. carbohydrates. d. nucleic acids. e. steroids.

b. proteins.

In this reaction, ATP synthase uses energy from ______ to make ATP. a. protons stripped from water b. protons reentering the cell c. electrons passed from cytochromes d. protons passed from cytochromes

b. protons reentering the cell

The process of decarboxylation involves: a. removing water b. removing carbon c. adding water d. removing hydrogen

b. removing carbon

During the electron transport chain in bacteria, protons are: a. shuttled to the inside of the membrane b. shuttled to the outside of the cell membrane c. carried along the transport chain d. attached to molecules in the glycocalyx

b. shuttled to the outside of the cell membrane

The electron carrier proteins in the electron transport chain shuttle electrons to: a. ribosomes b. a terminal acceptor c. ATP synthase d. transmembrane channels

b. terminal acceptor

The last carrier protein in the electron transport chain transfers: a. two protons to coenzyme Q b. two electrons to oxygen c. two electrons to ATP synthase d. two electrons outside the cell

b. two electrons to oxygen

Anabolism is the form of metabolism in which energy is...... important molecules. a. used to break down b. used to build c. released thought the breakdown of d. released through the assembly of

b. used to build

Many coenzymes are formed from a. metals b. vitamins c. proteins d. substrates

b. vitamins

ATP synthase complexes can generate... ATPs for each NADH that enters electron transport. a. 1 b. 2 c. 3 d. 4

c. 3

Complete oxidation of glucose in aerobic respiration can yield a maximum net output of.... ATPs. a. 40 b. 6 c. 38 d. 2

c. 38

Choose the statement that best describes glycolysis. a. A cyclic series of redox reactions which process pyruvic acid and release CO2 and generate ATP and NADH b. A series of redox reactions used to generate ATP using energy harvested from the transport of electrons from NADH and FADH2 c. A multistep process resulting in the enzymatic splitting and oxidation of glucose to form pyruvic acid, with a net gain of 2 ATP d. The series of catabolic reactions which break down pyruvate to form acetyl CoA and CO2

c. A multistep process resulting in the enzymatic splitting and oxidation of glucose to form pyruvic acid, with a net gain of 2 ATP

The chemical(s) in which energy is stored in cells is(are) ________. a. nucleotides b. metabolic inducers c. ATP d. enzymes

c. ATP

Which of the following contain a metal ion which can accept and donate electrons? a. Quinolones b. Fluorochromes c. Cytochromes d. Chelators

c. Cytochromes

Where do NADH and FADH2 go after being produced in the Krebs cycle? a. Fermentaion pathways b. The Calvin Cycle c. Electron transport chain d. Substrate-level phosphorylation

c. Electron transport chain

Which of the following statements best describes why this patient is exhibiting a high serum lactate? a. Lactate is a by-product of anaerobic respiration, allowing an alternatives source of energy in the presence of hypoxia. acetyl CoA is converted into oxaloacetic acid b. Lactate is administed to patients with hypoxia to improve oxygenation c. Lactate is a by-product of fermentation, allowing an alternative source of energy in the presence of hypoxia d. Lactate is a by-product of aerobic respiration, allowing an alternative source of energy in the presence of hypoxia

c. Lactate is a by-product of fermentation, allowing an alternative source of energy in the presence of hypoxia

The energy captured in the phosphorylation of ADP to ATP comes from the proton motive force created in respiration. True False

True

The protons are generated during oxidation reactions T/F

True

Select all of the statements below that are true of enzymes to test your understanding of their structure and function. a. Composed of protein b. Increase the rate of chemical reactions c. Are used up in chemical reactions d. High concentrations are necessary for activity e. Activity is affected by temperature and pH f. Activity is affected by regulatory mechanisms g. Become incorporated into the reaction product h. Have active sites with which substrates interact i. Increase the activation energy of a reaction

a, b, e, f, h

In the process of fermentation, what is the ATP yield per molecule of glucose? a. 2 ATP b. Fermentation does not yield ATP c. 36 ATP d. 38 ATP

a. 2 ATP

The two 3-carbon molecules which glucose is split into are converted through a series of steps into pyruvate. During these steps: a. NAD+ is converted to NADH b. acetyl CoA is converted into oxaloacetic acid c. ATP is converted to ADP d. NADH is converted to NAD+

a. NAD+ is converted to NADH

Choose the statement that most accurately expressed the significance of the electron transport system. a. The electron transport system transforms the energy of electrons into the potential energy of an electrochemical gradient (proton gradient) across the cell membrane (bacteria) or inner mitochondrial membrane (eukaryotes). This proton gradient provides the energy used by ATP synthase to phosphorylate ADP, producing ATP. b.The movement of electrons from one carrier to the next provides the energy necessary to split glucose. c. The role of the electron transport system is to dispose of electrons that were removed during glycolysis and Krebs cycle and use these electrons to make water. d. The electron transport system is instrumental in the creation of an electrochemical gradient of electrons across the cell membrane (bacteria) or inner mitochondrial membrane (eukaryotes). The electron gradient drives the phosphorylation of ADP by the ATP synthase enzyme.

a. The electron transport system transforms the energy of electrons into the potential energy of an electrochemical gradient (proton gradient) across the cell membrane (bacteria) or inner mitochondrial membrane (eukaryotes). This proton gradient provides the energy used by ATP synthase to phosphorylate ADP, producing ATP.

After glycolysis, pyruvate can be converted into ______ under anaerobic conditions. a. lactic acid b. cytochrome c c. acetone d. malic acid

a. lactic acid

The energy released during the reactions of glycolysis is released by ______ reactions. a. oxidation b. hydrolysis c. reduction d. dehydration

a. oxidation

How many net ATP molecules are produced for each glucose molecule that enters glycolysis? a. two b. six c. one d. three

a. two

Select the electron carriers used by cells. a. Glucose b. NAD c. FAD d. ATP e. CO2

b, c

During the electron transport chain, ATP will be made from: a. AMP + 2 Pi b. ADP + Pi c. Adenosine + P3 d. ADP + H20

b. ADP + Pi

_____________ refer(s) only to energy-requiring processes that result in synthesis of cell molecules and structures. a. Anabolism and metabolism b. Anabolism c. Metabolism d. Catabolism

b. Anabolism