Quiz 23: Metabolism and Energy Production

Which is the sum of all of the chemical reactions that take place in an organism? A)Anabolism B)Metabolism C)Catabolism D)Citric acid cycle

Where does energy production occur in animal cells? A)Cell membrane B)Cytoplasm C)Mitochondria D)Nucleus

Which is the first stage of catabolism? A)Digestion B)Citric acid cycle C)Fatty acid oxidation D)Glycolysis E)Formation of acetyl CoA

Where does the hydrolysis of carbohydrates to monosaccharides begin? A)In the stomach B)In the saliva C)In the liver D)In the small intestines

Which is the abbreviated structure of acetyl CoA? A) B) C) D)

If the phosphorylation of GMP to form GDP requires 7.3 kcal/mol of energy,what is the energy change associated with the hydrolysis of GDP to form GMP? A)7.3 kcal/mol B)-7.3 kcal/mol C)14.6 kcal/mol D)Not enough information is given to determine the change in energy.

Considering the energy changes associated with the two individual reactions below,what coupled reaction is an energetically favorable one? A)Fructose 1,6-bisphosphate + H₂O fructose 6-phosphate + HPO₄^2- B)ADP + fructose 1,6-bisphosphate ATP + fructose 6-phosphate C)ATP + H₂O ADP + HPO₄^2- D)ADP + fructose 6-phosphate ATP + fructose 1,6-bisphosphate E)ATP + fructose 6-phosphate ADP + fructose 1,6-bisphosphate

Considering the energy changes associated with the two individual reactions below,what is the energy change associated with the energetically favorable coupled reaction? A)- 11.2 kcal/mol B)- 3.4 kcal/mol C)- 7.3 kcal/mol D)+ 3.4 kcal/mol E)+ 11.2 kcal/mol

Which molecule contains the largest amount of stored energy? A) B) C) D)

The addition of a phosphate group to ADP,forming ATP,is an example of what type of reaction? A)Hydration B)Hydrolysis C)Phosphorylation D)Reduction E)Decarboxylation

Considering the energy changes associated with the individual reactions below,which reaction can be coupled with the hydrolysis of ATP to generate a coupled reaction that is energetically favorable? A)Fructose 6-phosphate + HPO₄^2- fructose 1,6-bisphosphate + H₂O B)Succinate + HSCoA + HPO₄^2- succinyl CoA + H₂O C)3-phosphoglycerate + HPO₄^2- 1,3-bisphosphoglycerate + H₂O D)All of the reactions can be coupled with the hydrolysis of ATP to generate a coupled reaction that is energetically favorable.

Which is not true about coenzymes? A)Many reactions in metabolic pathways involve coenzymes. B)When a coenzyme gains hydrogen atoms the coenzyme is an oxidizing agent. C)Many coenzymes are involved in oxidation and reduction reactions. D)The coenzyme nicotinamide adenine dinucleotide,NAD⁺,is a common biological reducing agent.

Which coupled reaction properly indicates the role of the coenzyme as an oxidizing agent? A) B) C) D)

Which functional group is not contained in coenzyme A,whose structure is shown below? A)Alcohol B)Sulfhydryl C)Phosphoester D)Amide E)Aldehyde

How many molecules of CO₂ are produced for each turn of the citric acid cycle? A)1 B)2 C)4 D)8

How many molecules of GTP are produced for each turn of the citric acid cycle? A)1 B)2 C)4 D)8

How many molecules of ATP are produced for each unit of GTP formed in the citric acid cycle? A)4 B)3 C)2 D)D1

How many molecules of reduced coenzymes are produced for each turn of the citric acid cycle? A)2 B)4 C)16 D)32

How many reactions make up the citric acid cycle? A)3 B)4 C)6 D)8

What is the classification of the reaction shown? A)Redox B)Isomerization C)Decarboxylation D)Hydrolysis

What is the classification of the reaction shown? A)Oxidation B)Reduction C)Decarboxylation D)Hydrolysis E)Isomerization

How many carbons enter into the citric acid cycle with each new Acetyl CoA? A)1 B)2 C)4 D)6

Which steps of the citric acid cycle generate reduced coenzymes necessary in the production of ATP? A)Steps 2,3,4,and 7 B)Steps 1,4,7,and 8 C)Steps 3,4,5,and 7 D)Steps 3,4,6,and 8

Which steps of the citric acid cycle generate CO₂? A)Steps 2 and 3 B)Steps 3 and 4 C)Steps 4 and 5 D)Steps 5 and 6

How much ATP is generated for each acetyl CoA during stages [3] and [4] of catabolism? A)4 molecules of ATP B)5 molecules of ATP C)8 molecules of ATP D)10 molecules of ATP E)16 molecules of ATP

Why is hydrogen cyanide,HCN,poisonous? A)HCN is a strong acid,dramatically altering the pH in cells. B)Cyanide ions (^-CN)irreversibly bind to the Fe³⁺ ion of cytochrome oxidase. C)Cyanide ions (^-CN)irreversibly bind to acetyl CoA. D)Cyanide ions (^-CN)irreversibly bind to NAD⁺.

In which stage of metabolism are biomolecules degraded into two-carbon acetyl units? A)Stage [1] B)Stage [2] C)Stage [3] D)Stage [4]

Which is the primary energy-carrying molecule in metabolic pathways? A)AMP B)ATP C)NADH D)Acetyl CoA E)FADH₂

Where does the electron transport chain process take place? A)In the inner membrane of mitochondria B)In the outer membrane of mitochondria C)In the intermembrane space of mitochondria D)In the matrix of mitochondria

In which stage of catabolism is starch hydrolyzed to glucose with the aid of the enzyme amylase? A)Stage [1] B)Stage [2] C)Stage [3] D)Stage [4]

Which is an oxidizing agent? A)Fe²⁺ B)NAD⁺ C)FADH₂ D)ATP

Which statement best describes what occurs with a substrate is oxidized using FAD to product FADH₂? A)FAD is a reducing agent,and FADH₂ is its oxidized form. B)FAD is a reducing agent,and FADH₂ is its reduced form. C)FAD is an oxidizing agent,and FADH₂ is its oxidized form. D)FAD is an oxidizing agent,and FADH₂ is its reduced form.

Which intermediate in the citric acid cycle is a secondary alcohol? A) B) C) D) E)Two of the intermediates are secondary alcohols.

Which intermediate in the citric acid cycle contains two chirality centers? A) B) C) D)

How many reactions in the citric acid cycle generate FADH₂? A)0 B)1 C)3 D)8

How many reactions in the citric acid cycle generate NAD⁺? A)0 B)1 C)3 D)8

Which product(s)of the citric acid cycle are funneled into the electron transport chain? A)ATP B)NAD⁺ and FAD C)NADH,FADH₂,and H⁺ D)NADH,FADH₂,H⁺,and ATP

In which region of a mitochondrion would the pH be lower? A)The matrix B)The intermembrane space C)The inner mitochondrial membrane D)All regions of a mitochondrion have the same pH

Which is not a reaction found in stage [2] of catabolism? A)Fatty acid oxidation B)Glycolysis C)Oxidative phosphorylation D)Amino acid catabolism

Which is the major product of stage [2] of catabolism? A)NADH B)Acetyl CoA C)GTP D)CO₂

Which is the enzyme that hydrolyzes triacylglycerols? A)Acetyl CoA B)Protease pepsin C)Amylase D)Lipase

Which statement concerning the digestion of food groups is incorrect? A)Carbohydrates are ultimately broken down to glucose and other monosaccharides. B)Triacylglycerols are ultimately broken down by lipases into glycerol and fatty acids. C)Proteins are ultimately broken down by proteases into amino acids. D)Polysaccharides are ultimately broken down to nucleotides.

What is the primary function of the citric acid cycle in metabolism? A)To break down food molecules into smaller components so they can be absorbed by the blood B)To synthesize ATP from the energy produced in the hydrolysis of citric acid C)To provide the enzymes necessary to aid in the hydrolysis of carbohydrates,proteins,and lipids D)To convert acetyl groups to CO₂ molecules and provide reduced coenzymes for the electron transport chain

At which stage of metabolism is the most energy in the form of ATP produced? A)Electron transport chain and oxidative phosphorylation B)Digestion C)Citric acid cycle D)Transcription

Which best describes the function of the coenzymes NAD⁺ and FAD in catabolic pathways? A)Competitive inhibitors of the enzymes present in each pathway B)Noncompetitive inhibitors of the enzymes present in each pathway C)Oxidizing agents that accept electrons and hydrogen ions from molecules undergoing oxidation D)Transport molecules that carry acetyl units to or from the different stages of metabolism

The primary function of the electron transport chain and oxidative phosphorylation is which of the following? A)To provide electrons and energy for the phosphorylation of ATP B)To synthesize the reduced coenzymes necessary for digestion C)To oxidize the reduced coenzymes NADH and FADH₂,and provide energy for the synthesis of ATP D)To transport electrons from ATP to ADP,and synthesize acetyl CoA molecules

Each NADH that enters the electron transport chain will result in the formation of ________ units of ATP. A)10 B)2.5 C)1.5 D)32 E)7.3

Each FADH₂ that enters the electron transport chain will result in the formation of ________ units of ATP. A)7.3 B)10 C)1.5 D)2.5 E)32

Which statement best describes how the interconversion of ATP and ADP is responsible for storing and providing energy for cellular reactions? A)The energy stored in ADP is released when ATP is synthesized. B)The energy required to phosphorylate ADP is stored in ATP,and released when ATP undergoes hydrolysis. C)The energy released in the phosphorylation of ADP can be coupled with unfavorable reactions within the cell. D)The energy required to hydrolyze ATP comes from the energy producing reactions in the cell; the energy lost is then stored in ATP.

Oxaloacetate is the starting material in the first step of the citric acid cycle and the product of the last step. The last step of the citric acid cycle,the oxidation of malate to oxaloacetate,is shown. What is the structure of oxaloacetate? A) B) C) D)

The second step of the citric acid cycle,the isomerization of citrate to isocitrate,is shown. What is the structure of isocitrate? A) B) C) D)

Step 7 of the citric acid cycle is shown. Which statement best describes what occurs in this step? A)Fumarate undergoes hydrolysis with the aid of the enzyme fumarase. B)Fumarate undergoes reduction with the aid of the cofactor fumarase. C)Fumarate undergoes hydrogenation with hydrogens and electrons provided by the enzyme fumarase. D)Fumarate undergoes hydration with the aid of the enzyme fumarase.

Step 6 of the citric acid cycle is shown. Which statement best describes the role of FAD in this reaction? A)FAD causes the reduction of succinate to form fumarate. B)FAD causes succinate to undergo hydration to form fumarate. C)FAD causes the oxidation of succinate to form fumarate. D)FAD causes the isomerication of succinate to form fumarate.

Since more energy is released from the hydrolysis of creatine phosphate than is needed for the phosphorylation of ADP,the coupling of these two reactions results in the formation of ATP from ADP.

Coenzyme A is a biological oxidizing agent used to convert alcohols to carbonyl-containing compounds.

Coenzyme A is synthesized in cells from pantothenic acid,vitamin B₅.

The citric acid cycle is also called the tricarboxylic acid cycle (TCA cycle).

All steps of the citric acid cycle are enzyme catalyzed.

The citric acid cycle is activated with the amount of available ADP is low.

NAD⁺ and FAD are oxidized in the electron transport chain.

The electron transport chain is a multistep process that relies on five enzyme systems as well as mobile electron carriers.

The final stage of the electron transport chain forms water in an anaerobic process.

The conversion of Fe³⁺ to Fe²⁺ in the electron transport chain is an example of Fe³⁺ acting as an oxidizing agent.

H⁺ ions generated by reactions in the electron transport chain,as well as H⁺ ions present in the matrix of the mitochondria,are pumped across the inner mitochondrial membrane into the intermembrane space at three different sites.

Energy released from H⁺ movement in the electron transport chain fuels the phosphorylation of ADP.

NAD⁺ is the abbreviation for nicotinamide adenine dinucleotide.

The citric acid cycle comprises stage [4] of metabolism.

In the electron transport chain,H⁺ ions are pumped across the inner membrane of the mitochondrion,forming a high concentration of H⁺ ions in the intermembrane space,thus creating a potential energy gradient.

The terms phosphorylation and oxidative phosphorylation may be used interchangeably.

Stage [3] of catabolism is sometimes called aerobic respiration.

The cells in heart tissue have more mitochondria than the cells in bone tissue.

Each NADH enters the electron transport chain at complex I in the inner mitochondrial membrane and the resulting cascade of reactions produces enough energy to synthesize 4 ATPs.

The reaction shown below requires the overall input of energy.

The structure of flavin adenine dinucleotide (FAD)is shown here.

Acetyl CoA contains an acetyl group bonded to coenzyme A by a thioester bond.

Part [2] of the citric acid cycle includes two separate decarboxylation reactions and a hydrolysis reaction.

The rate of the citric acid cycle depends on the body's need for energy. When energy demands are low and NADH concentration is high,the cycle is inhibited.

Two electrons are donated by each NADH in the electron transport chain.

The cleavage of a protein with chymotrypsin occurs in stage [1] of catabolism.

GTP is a high energy compound.

Any energy requiring reaction can be coupled with ATP hydrolysis to create an energetically favorable coupled reaction.

The structure of coenzyme A contains amine and amide functional groups.

Coenzyme A,NADH,and FAD all contain phosphate groups.

The primary function of the electron transport chain and oxidative phosphorylation is to provide electrons for the hydrolysis of ATP.

The primary function of the citric acid cycle in metabolism is to synthesize ATP from the energy produced in the hydrolysis of citric acid.

Anabolism is an energy releasing process that involves the synthesis of large molecules from smaller ones.

Within the cell,energy production occurs in the matrix of the mitochondrion.

The product of the catabolic pathways is different for proteins,triacylglycerols,and carbohydrates.

The energy produced by the citric acid cycle is stored in the bonds of a nucleoside triphosphate and reduced coenzymes.

The hydrolysis of ATP is an energy-requiring reaction that cleaves one phosphate group,forming ADP and hydrogen phosphate,(HPO₄^2-).

Any process,such as walking,running,swallowing,or breathing,is fueled by the release of energy from the phosphorylation of ADP to ATP.

Coupled reactions are pairs of reactions that occur together so that the energy released by one reaction provides the energy to drive the other reaction.

The phosphorylation of glucose provides enough energy for the hydrolysis of ATP.

________ is the breakdown of large molecules into smaller ones.

________ is a coenzyme synthesized in cells from vitamin B₂,riboflavin.

________ is a cyclic metabolic pathway that begins with the addition of acetyl CoA to a four-carbon substrate and ends when the same four-carbon compound is formed as a product eight steps later.

The main function of the citric acid cycle is to produce ________ that enter the electron transport chain and ultimately produce ________.

The reduced coenzymes formed in the citric acid cycle enter the ________.

At the end of the electron transport chain,the electrons and protons (obtained from the reduced coenzymes or the matrix of the mitochondrion)react with inhaled oxygen to form ________.

By the end of step [4] of the citric acid cycle,________ carbons are lost as CO₂ and ________ molecules of NADH are formed.

Protein digestion begins in the ________.

The number of moles of ATP that can be synthesized from ADP using the 750. Calories ingested during a meal is ________ moles.