Chapter 4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 125) What are the five ways that cells regulate flow of molecules through their metabolic pathways?

: 1. by controlling the enzyme concentration 2. by producing modulators (allosteric and covalent) 3. by using two different enzymes to catalyze reversible reaction 4. by isolating enzymes within intracellular organelles (compartments) 5. by maintaining an optimum ratio of ATP to ADP Section Title: Metabolism Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 119) Consider the two chemical reactions. Identify each statement following as true or false, and clarify as needed. A + B → C C → A + B A. The enzyme catalyzing the formation of C must be different from that catalyzing the breakdown of C. B. The enzyme catalyzing the formation of C must be the same as that catalyzing the breakdown of C. C. Only one of the reactions could occur in a given cell or system. D. Both reactions must be occurring in an equilibrium situation. E. Equilibrium is always achieved in a chemical reaction. F. Equilibrium can be prevented from occurring by constantly removing the product of either reaction. G. An equilibrium, once established, cannot be disturbed.

: A. False. There may be more than one enzyme for the reactions listed, but a given enzyme is often capable of performing a reaction in both directions. B. False. The enzyme for both reactions could be the same, but often a particular enzyme is more likely to perform the forward reaction while a different enzyme is more likely to perform the reverse. C. False. If the reactions are at equilibrium, both are occurring at the same time. If they are not at equilibrium, it is possible that the reaction is occurring only in one direction. In addition, cells can have different enzymes for each reaction direction that can be differentially controlled (i.e., one active and the other inactive). D. True. By definition, a reaction is at equilibrium when both directions are occurring such that there is no net change in amounts of substrates and products. E. False. Equilibrium is not necessarily established, especially in a cell where a product is immediately removed from the system for use elsewhere, such as the product ATP, or if a given enzyme does not perform the reverse reaction. F. True. Any change in amounts of enzyme, substrate, or product will disturb equilibrium, and if these things constantly change, equilibrium cannot be established. G. False. Equilibrium can be disturbed by changing the amount of enzyme, substrate, or product, or by altering the enzyme's efficacy by changing temperature or pH. Section Title: Enzymes Learning Outcome: 4.2

: Level III: Problem Solving (Bloom's Taxonomy: Analysis) 139) For the following strand of DNA, use the table below to provide: bases for the complementary mRNA and bases for the corresponding tRNA molecules and the associated amino acids. What do you notice about the relationship between the DNA and the anticodons? What do you notice about the genetic code for proline in the peptide? How would the loss of the first G or switching that G to a T affect the structure and function of this protein? DNA: GGC CTA CAA GCC GGA ACA GTT ACC GCG TAA CGA mRNA: tRNA:

: mRNA: CCG GAU GUU CGG CCU UGU CAA UGG CGC AUU GCU tRNA: GGC CUA CAA GCC GGA ACA GUU ACC GCG UAA CGA protein: pro asp val arg pro cys gln trp arg ile ala The DNA triplets and the tRNA anticodons are identical except that U (in tRNA) substitutes for T (in DNA). In this peptide, proline was specified by two different codons, CCG and CCU. 1 base lost: arg met phe gly leu val asn gly ala leu 1 base altered: thr asp val arg pro cys gln trp arg ile ala Loss of a base results in dramatic changes in the protein structure (1 less amino acid and a start codon at the second codon) which means the proteins is unlikely to be functional. However, a single base substitution would have a single amino acid different which make the proteins more likely to be functional although the function may still be altered. Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 3) According to the second law of thermodynamics, A) the amount of entropy in living systems increases without the input of energy. B) entropy decreases in living systems that are not receiving energy. C) energy can be converted, but not be created nor destroyed. D) the total amount of energy in the universe never changes.

: A Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 59) carbonic anhydrase

: A Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 10) When a chemical reaction is in equilibrium, A) there is no net change in the amount of substrates or products. B) the reaction is proceeding at its maximum rate. C) the reaction has stopped. D) there are equivalent amounts of substrates and products.

: A Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 8) Isozymes A) are enzymes with slightly different structure that catalyze the same reaction. B) are enzymes with the same structure that catalyze different reactions. C) are inorganic molecules that bind to and thereby activate enzymes. D) are the inactive form of an enzyme.

: A Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 9) Enzymes increase reaction rate by A) lowering the activation energy of a reaction. B) increasing the free energy in the products. C) raising the activation energy of a reaction. D) converting an endergonic reaction to an exergonic reaction.

: A Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 97) The rate of product formation by an enzyme-catalyzed reaction would be increased by A) adding more substrate molecules. B) adding more product molecules. C) reducing the number of enzymes. D) reducing the number of substrate molecules.

: A Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 38) An example of transamination is A) removing an amine group from one molecule and binding it to a different molecule. B) removing an amino group and putting it into the bloodstream for the kidneys to discard. C) removing a phosphate group from a molecule. D) finding a brand new sports car in your driveway with your name on it.

: A Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 20) An enzyme that adds or subtracts water molecules is a A) hydrolase. B) lipase. C) transferase. D) ligase. E) kinase.

: A Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 52) dehydrogenase

: A Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 17) An allosteric modulator binds to A) a region of the enzyme other than the active site. B) the active site. C) the substrate. D) the product. E) the surrounding tissue.

: A Section Title: Metabolism Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 107) The protein in the mitochondria that captures the kinetic energy of moving H+ ions and converts it to the stored energy of ATP is called A) ATP synthase. B) lactate dehydrogenase. C) oxidative phosphorylase. D) glucokinase.

: A Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 50) Following post-translational modification, any misfolded protein will be destroyed by A) ubiquitin. B) chaperones. C) methylation. D) ribonucleases.

: A Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 44) Transcription occurs in the ________ of the cell. A) nucleus B) cytoplasm C) Golgi apparatus D) smooth endoplasmic reticulum E) plasma membrane

: A Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 41) The TAC sequence of DNA is the ________ of a coding sequence that is preceded by the ________ that regulates transcription. A) start, promoter region B) start, intron C) stop, promoter region D) stop, intron

: A Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 114) If the enzyme RNA polymerase was completely inhibited within a cell, it could not A) form proteins. B) form complementary sequences of DNA. C) link pieces of DNA together. D) form spindle fibers. E) form a new nuclear membrane during cell division.

: A Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 110) Transcription of the DNA triplet sequence ATC yields A) UAG. B) TAG. C) UTC. D) ATC.

: A Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 122) Explain what a concentration gradient is and how it assists a cell in doing its work.

: A concentration gradient is a difference in concentration of a particular molecule between the cytosol of a cell and the interstitial fluid. A concentration gradient represents potential energy because of the tendency of molecules to diffuse from areas of high to areas of low concentration. Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 92) What are the advantages of using ATP as the energy-transferring molecule in a cell?

: ATP easily acquires the energy stored in complex biomolecules such as carbohydrates and its phosphate bonds are readily broken to release energy. Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 71) The activity of metabolic pathways is influenced by the ratio of ________.

: ATP to ADP Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 7) A reversible reaction is one where A) there are large changes in the net free energy from substrate to product. B) there are small changes in the net free energy from substrate to product. C) there is no change in the net free energy from substrate to product. D) a reaction between products is unlikely due to the high activation energy.

: B Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 94) An exergonic chemical reaction A) converts substrates into products that have more free energy. B) releases energy as the reaction progresses. C) requires the input of energy. D) requires an enzyme in order to overcome the activation energy.

: B Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 55) kinase

: C Section Title: Enzymes Learning Outcome: 4.3

Human Physiology: An Integrated Approach, 6e (Silverthorn) Chapter 4 Energy and Cellular Metabolism 1) Energy is defined as A) doing tasks that make you tired. B) the capacity to do work. C) the light and heat from the sun. D) using glucose to synthesize ATP.

: B Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) In the reaction shown, identify the role of each of the participants. CO2 + H2O H2CO3 A. enzyme B. substrate(s) C. product(s) 58) CO2 + H2O

: B Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 22) A molecule that loses electrons during a reaction is A) reduced. B) oxidized. C) dehydrated. D) hydrated.

: B Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 54) lipase

: B Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 53) dehydratase

: B Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 16) A competitive inhibitor binds to A) a region of the enzyme other than the active site. B) the active site. C) the substrate. D) the product. E) the surrounding tissue.

: B Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 23) The active sites of enzymes are A) products of an enzymatic reaction. B) regions of an enzyme that are involved in bringing substrates together. C) bonds between the substrate and certain amino acids. D) not necessarily involved in a reaction.

: B Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 28) Compartmentation refers to A) pairing together isozymes that perform similar reactions. B) grouping related enzymes into specific organelles. C) separating substrates into chemical classes. D) dividing metabolic reactions into groups for better understanding.

: B Section Title: Metabolism Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Analysis) 99) Cells normally regulate the rate of an enzymatic reaction by A) raising their temperature to 110° F. B) changing the concentration of an enzyme. C) increasing reaction rate as the concentration of product increases. D) allowing all metabolic enzymes to be found throughout the cytoplasm.

: B Section Title: Metabolism Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 101) In order to slow generation of product from a particular biochemical pathway within a cell, the intermediates formed by that pathway A) are removed from the cell more quickly. B) accumulate inside the cell. C) are rapidly converted into. D) become toxic to the cell.

: B Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 34) What is the potential yield of ATP molecules for each FADH2 molecule entering the electron transport system? A) 1 B) 1.5 C) 2 D) 2.5 E) 3

: B Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 27) When energy is released during catabolism, it is temporarily trapped in high energy bonds or electrons of certain compounds. Which of the following is NOT associated with carrying energy? A) ATP B) DNA C) NADH D) FADH2 E) NADPH

: B Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 31) In the aerobic metabolism of glucose, ________ acts as the final electron acceptor. A) water B) oxygen C) carbon dioxide D) lactate E) ATP

: B Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 35) Why is there a range of 30-32 ATP molecules produced from one glucose molecule? A) Sometimes the electron transport system is more efficient than other times. B) The NADH molecules produced during glycolysis are in the cytoplasm; occasionally, electrons are carried by the lower energy FADH2 instead of NADH. C) Individual variation is normal among cells. D) Any of these answers may work under different cellular conditions.

: B Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 102) Which of the following is a key intermediate of glucose catabolism to the citric acid cycle? A) ATP B) pyruvate C) oxygen D) lactate E) glucokinase

: B Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 42) All of the triplet codes needed to produce exactly one functional piece of RNA are found in one A) chromosome. B) gene. C) codon. D) anticodon. E) None of the answers are correct.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 39) The process of forming mRNA is called A) replication. B) transcription. C) translation. D) ribolation. E) protein synthesis.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 48) The tRNA molecule contains the three-base sequence called the A) codon. B) anticodon. C) semicodon. D) aminocodon.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 45) The enzymes that synthesize mRNA from the start codon are called A) ribonucleases. B) RNA polymerases. C) DNA polymerases. D) ATP synthases. E) lactate dehydrogenases.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 49) In the absence of a signal sequence, a newly synthesized protein localizes to the A) mitochondria. B) cytoplasm. C) peroxisome. D) nucleus. E) plasma membrane.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 112) The template strand of DNA A) is not involved in mRNA synthesis. B) serves as a guide for mRNA synthesis. C) includes the base uracil. D) is alternatively spliced to generate the exon.

: B Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 118) Explain how these statements differ, and identify which one(s) is/are correct. Explain what is wrong with each incorrect statement. Explain when chemical reactions continue and when they stop. A. A chemical reaction proceeds until the enzyme molecules are all consumed. B. A chemical reaction proceeds until the substrate molecules are all consumed. C. A chemical reaction proceeds until equilibrium is established. D. A chemical reaction proceeds until all the product molecules are removed.

: B and C are correct as written, but B requires some clarification. A is incorrect because enzyme molecules are not consumed in chemical reactions and will continue to be active until acted upon by environmental conditions (temperature, pH, or modifiers). B is correct only when the product is removed from the system. If the product remains, the enzyme will reach equilibrium where the ratio of substrate to product is constant (Correct Answer C). In D, if the product of the reaction is removed, the reaction would continue to proceed to form new product (assuming enzymes and substrates are available). Chemical reactions continue if conditions are favorable, including presence of substrate and enzyme and fairly constant temperature and pH. In living systems, most chemical reactions do not have a steady supply of substrate; for example, the chemical reactions of digestion will stop when the small intestine is empty. Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 24) When an enzyme is working as fast as it can because its active site is continually refilled with substrate, the condition is referred to as A) allosteric modulation. B) equilibrium. C) saturation. D) the Ricardo-Mertz phenomenon. E) specificity.

: C Section Title: Metabolism Learning Outcome: 4.2

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 137) Explain how it is possible for an enzyme to catalyze a chemical reaction in two different directions.

: Both the substrate and product have a 3-D shape complementary to the active site of the enzyme. In a synthesis reaction between two organic monomers, the enzyme holds the substrates in a position that greatly increases the likelihood of bond formation between them, and as the bond forms to produce a dimer, the affinity of the enzyme for the substrates increases. The dimer is also complementary to the active site of the enzyme, and if a dimer molecule happens to bind to the enzyme, becoming the substrate, the bond between the monomers becomes strained as the intermediate is formed and can break. If this happens, the reaction is a degradation and the products are the monomers. The tightest binding is between the enzyme and the intermediate form, different in structure compared to either the substrates or the product. Thus it is equally likely that the reaction will be a synthesis or a degradation, if no other factors are considered. Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 6) Activation energy is A) the energy lost or gained in a reaction. B) the energy required for an endergonic reaction. C) the energy required to bring molecules into a position where they can interact. D) required to convert an endergonic reaction to an exergonic reaction.

: C Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 60) H2CO3

: C Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 11) Organic molecules that act as receptors/carriers for the cleaved portion of the substrate are A) vitamins. B) isoenzymes. C) coenzymes. D) modulators.

: C Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 12) The activity of an enzyme is changed by environmental factors such as temperature or pH; these factors are referred to as A) specificity. B) common bond. C) modulators. D) isozyme. E) product.

: C Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 96) Enzymes are often useful as diagnostic tools. How? A) Enzymes destroy pathogenic bacteria so blood levels of bacteria decline. B) Enzymes destroy damaged cells so X-rays reveal smaller body organs. C) Damaged cells release enzymes into the blood that can be detected. D) The liver releases enzymes that accumulate in the urine.

: C Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 98) Changes in environmental pH or temperature will cause the reaction rate for an enzyme to A) increase. B) decrease. C) either increase or decrease depending upon enzyme properties. D) not change.

: C Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 18) An enzyme that transfers chemical groups among substrates is a A) hydrolase. B) lipase. C) transferase. D) ligase. E) kinase.

: C Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 30) The reactions of glycolysis occur in the cell's ________; the reactions of the citric acid cycle occur in the ________. A) cytoplasm, cytoplasm B) mitochondria, mitochondria C) cytoplasm, mitochondria D) mitochondria, cytoplasm

: C Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 33) For each NADH molecule that moves through the electron transport system, what is the potential yield of ATP molecules? A) 1 B) 2 C) 2.5 D) 3.5 E) 4

: C Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 104) Inside the matrix of the mitochondria, pyruvate A) is converted to acetyl CoA which requires energy from an NADH. B) gains a carbon in its conversion to acetyl CoA. C) requires the vitamin pantothenic acid for its conversion to acetyl CoA. D) is converted to lactate under anaerobic conditions.

: C Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 103) The net energy yield for the anaerobic metabolism of one glucose molecule is A) 2 ATP and 2 NADH. B) 0 ATP and 2 NADH. C) 2 ATP and 0 NADH. D) 2 ATP and 2 FADH2. E) 2 ATP, 6 NADH, and 2 FADH2.

: C Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 108) What happens to the oxygen that is metabolized within the mitochondria? A) The oxygen is converted to CO2. B) The oxygen is incorporated into organic molecules during cellular metabolism. C) The oxygen is combined with hydrogen to form water. D) The oxygen acts as a coenzyme in the production of ATP. E) The oxygen is converted to CO2 and is combined with hydrogen to form water.

: C Section Title: Metabolism Learning Outcome: 4.5

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 106) Oxidative phosphorylation occurs ________; the beneficial end product is ________. A) in the cytoplasm just inside the plasma membrane, H2O B) in the cytoplasm just inside the plasma membrane, ATP C) in the mitochondria due to the electron transport system, ATP D) in the mitochondria due to the electron transport system, CO2 E) twice during the citric acid cycle, ATP

: C Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 46) To activate a regulated gene, the formation of mRNA is ________ by the binding of ________ to the promoter. A) repressed, transcription factors B) repressed, translation factors C) induced, transcription factors D) induced, translation factors

: C Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 43) Information stored in the nucleus is translated into A) carbohydrates. B) lipids. C) proteins. D) phospholipids. E) None of the answers are correct.

: C Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 111) Transcription of the DNA triplet sequence CAT will bind to the tRNA bearing A) CAT. B) GTA. C) GUA. D) ATU.

: C Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 109) What is the result of alternative splicing of mRNA? A) A new gene is produced. B) The DNA is replicated. C) Isoenzymes are produced from a single gene. D) Genes are mutated. E) Proteins isomerize.

: C Section Title: Metabolism Learning Outcome: 4.6

: Level IV: Quantitative Problems (Bloom's Taxonomy: Application) 143) Carbon dioxide and water readily combine to form carbonic acid. The change in pH as the acid dissociates can be demonstrated with an indicator dye that changes color at a particular pH. In your physiology lab, you perform this experiment in two beakers containing room-temperature water and indicator, labeled as A and B. CO2 is bubbled into solutions A and B from a pressurized tank for 10 seconds. A stopwatch was used to measure how long it took for the solutions to change color. The data below were generated by the students. Student Time for reaction (seconds): Solution A Time for reaction (seconds): Solution B 1 62 1 2 58 2 3 57 3 Write the chemical equation for this reaction. Determine average values for each beaker. Explain how the reaction times differed. What may be present in beaker B that is absent from beaker A?

: CO2 + H2O → H2CO3 → H+ + HCO3- Average time for beaker A to change is 59 seconds, and for beaker B to change is 2 seconds, that is, the reaction occurred faster in solution B. For this to occur, an enzyme such as carbonic anhydrase must have been present in beaker B. Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 127) Candy bars are well known to supply large amounts of energy for metabolism. With all this energy trapped inside, how can the candy bar sit still on the shelf in the grocery store?

: Candy bars contain large amounts of energy, but it is trapped as potential energy in carbohydrates (both simple and complex). The carbohydrates must be broken down and enter the cell's metabolic pathways in order to convert the potential energy to another form. Section Title: Metabolism Learning Outcome: 4.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 129) What is chemiosmotic theory? What is its role in metabolism?

: Chemiosmotic theory is a model that explains the movement of electrons through the electron transport system. This occurs across the mitochondrial inner membrane and drives oxidative phosphorylation and production of ATP by ATP synthase. Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 4) Chemical reactions in a living system function to A) only transfer energy from one molecule to another. B) create new energy. C) only use energy stored in a molecule. D) transfer energy from one molecule to another or use energy stored in a molecule.

: D Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 5) The ________ of glycogen from many glucose molecules is an ________ reaction. A) decomposition, endergonic B) synthesis, exergonic C) decomposition, exergonic D) synthesis, endergonic

: D Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 25) Which of these results in a REDUCED molecule? A) loss of phosphate B) gain of phosphate C) loss of electrons D) gain of electrons

: D Section Title: Enzyme Learning Outcome: 4.3

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 95) How would the lack of a required cofactor for an enzyme affect that enzyme's function? A) The enzyme's function would not be altered. B) The enzyme would function more slowly. C) The enzyme would function more quickly. D) The enzyme would not be able to function.

: D Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 19) An enzyme that joins two substrates using energy is a A) hydrolase. B) lipase. C) transferase. D) ligase. E) kinase.

: D Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) Match the specific enzyme to its class. A. oxidoreductase B. hydrolase C. transferase D. ligase E. lyase 51) synthetase

: D Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 13) The addition of a phosphate group to a substrate is called ________. The enzyme that catalyzes this reaction is referred to as a ________. A) proteolysis; phosphatase B) phosphorylation; phosphatase C) proteolysis; kinase D) phosphorylation; kinase

: D Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 26) End-product inhibition describes the process whereby A) decreasing amounts of substrate reduce activity of the enzyme. B) decreasing amounts of product reduce activity of the enzyme. C) increasing amounts of substrate reduce activity of the enzyme. D) increasing amounts of product reduce activity of the enzyme. E) increasing amounts of product reduce activity of all enzymes in the vicinity.

: D Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 32) The explanation for how ATP bonds are actually formed during oxidative phosphorylation is called A) the Krebs hypothesis. B) the second law of thermodynamics. C) the proton principle. D) the chemiosmotic theory. E) Murphy's law.

: D Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 29) Aerobic metabolism of glucose A) requires oxygen. B) produces more ATP per glucose than anaerobic pathways. C) is the fastest way to produce glucose. D) requires oxygen and produces more ATP per glucose than anaerobic pathways.

: D Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 105) NADH is produced from each reaction described except one. Identify the exception. A) during aerobic glycolysis B) during the conversion of pyruvate to acetyl CoA C) during the citric acid cycle D) during anaerobic glycolysis

: D Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 37) ATP synthase transfers the ________ energy of the H+ ions to the high-energy phosphate bond of ________. A) potential, NADH B) potential, ATP C) kinetic, NADH D) kinetic, ATP E) None of the answers are correct.

: D Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 40) After forming a complex with the ribosome, mRNA interacts with a third molecule. This molecule is called A) DNA. B) an amino acid. C) rRNA. D) tRNA. E) rough ER.

: D Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 47) Once synthesized, the ________ of mRNA are removed through ________, which results in the formation of the coding sequence of a protein. A) exon, RNA interference B) exon, alternative splicing C) intron, RNA interference D) intron, alternative splicing

: D Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 100) Increasing ________ will decrease the amount of mRNA transcript within a cell for a constitutively active gene. A) ribonuclease activity only B) RNA polymerase activity only C) siRNA concentration only D) ribonuclease activity and siRNA concentration only E) ribonuclease activity, RNA polymerase activity and siRNA concentration

: D Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 79) The enzyme ________ and ________ ions are required for the synthesis of mRNA.

: RNA polymerase, magnesium or manganese Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 113) During starvation, steroid hormones trigger the transcription of genes for lipid metabolism in their target cells. This would be an example of control by A) negative feedback. B) positive feedback. C) repressors. D) inducers. E) alternative splicing.

: D Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 115) Regulatory-protein transcription factors bind to ________ and activate ________, which tells the RNA polymerase ________.

: DNA, promoter, where to bind to the DNA Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 128) A certain reaction pathway consists of four steps. How would decreasing the amount of enzyme that catalyzes the second step affect the process?

: Decreasing the amount of enzyme at the second step would slow down the whole series of reactions because less product would be available as substrate for the next two steps. The net result would be a decrease in the rate of production of the product and therefore, within a specified time, a decrease in the amount of the product. Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 2) The general term that describes energy stored in chemical bonds is A) thermodynamics. B) bioenergetics. C) entropy. D) kinetic energy. E) potential energy.

: E Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 56) aminase

: E Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 57) deaminase

: E Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 14) Phosphate groups may be transferred from one molecule to another during A) hydrolysis reactions only. B) addition reactions only. C) dehydration reactions only. D) exchange reactions only. E) addition and exchange reactions.

: E Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 21) An enzyme that transfers phosphates from ATP to a substrate molecule is a A) hydrolase. B) lipase. C) transferase. D) ligase. E) kinase.

: E Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 15) When an enzyme's activity is destroyed by heat or a change in pH, the enzyme is said to be A) broken. B) toxic. C) conjugated. D) tertiary. E) denatured.

: E Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 36) Which can serve as substrates for ATP production? A) glucose only B) amino acids only C) fatty acids only D) glucose and fatty acids only E) glucose, amino acids and fatty acids

: E Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 124) Explain how the analogy of a ball and a hill is useful for describing the forms of energy to beginning physiology students. Use the synthesis of glucose by plants and the break down of glucose by humans as specific examples of the energy hill.

: Energy is required for a person to move a ball from a lower height to a higher one, and that the ball will automatically roll down the hill if allowed to, without further input of energy. The substrates CO2 and H2O require energy to be combined into C6H12O6; the energy of the sun provides this energy to "roll" the substrates up the energy hill as they combine. The glucose then contains the potential energy provided by the sun. When enzymes are present, the molecule easily breaks down to CO2 and H2O releasing energy that is used by the cell to perform work. Section Title: Enzymes Learning Outcome: 4.1

: Level III: Problem Solving (Bloom's Taxonomy: Analysis) 138) Glucose-6-phosphate (G6P) binds to the enzyme glycogen synthase (GS), increasing the probability of enzyme-substrate binding. G6P is an example of a(n) ________. Based on its name, what do you think is the role of GS?

: G6P is an example of an allosteric modulator of GS. GS is required for the synthesis of glycogen. Section Title: Enzymes Learning Outcome: 4.3

: Level IV: Quantitative Problems (Bloom's Taxonomy: Synthesis) 146) Bovine insulin is composed of 30 amino acids. What is the minimum number of DNA triplets in the insulin gene, based on the amino acid length? What is the minimum number of DNA bases in the coding region? Explain how and why the actual number of triplets in the gene may differ.

: Ignoring stop and start codons, RNA splicing, and post-translational modification, a peptide of 30 amino acids is specified by 30 triplets. As a triplet is 3 bases in length, this means a minimum of 90 DNA bases (30 triplets × 3 bases per triplet) is present in the insulin gene. The actual number of triplets and bases is higher, because the gene starts and ends with start and stop sequences, some of the mRNA codons are excised prior to translation and peptide sequence, and furthermore post-translational modification of the peptide may remove additional amino acids. Thus the number of amino acids in the peptide is related to gene length but doesn't allow precise calculation of gene length. Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 123) Carbonic acid is generated by bubbling CO2 into a beaker of water. If it took 5 minutes for this reaction to reach equilibrium, how would the results differ if the enzyme carbonic anhydrase was added to the beaker of water? Explain using the concept of the energy hill.

: In the presence of the enzyme, the reaction will occur much more rapidly thereby forming more carbonic acid. The enzyme lowers the activation energy for the reaction causing more product to be generated (i.e., carbonic acid). When the enzyme is present, the hill the ball must roll up before it can continue down the hill is lower than in the absence of the enzyme. Section Title: Enzymes Learning Outcome: 4.2

: Level III: Problem Solving (Bloom's Taxonomy: Analysis) 136) Some diseases, such as phenylketonuria, classical hemophilia, cystic fibrosis, and muscular dystrophy are a result of enzyme malfunction. Each of these diseases is inherited. Explain how there might be a relationship among these observations.

: Inheritance is determined by the message coded into DNA; a mutation relays a faulty message, which disrupts protein synthesis, resulting in either a faulty protein or complete absence of the protein. Enzymes are proteins. When the instructions for the synthesis of their structure are changed, they may not be able to perform their function, producing a disease condition. If the disease is not fatal prior to puberty and does not render its victim unable to reproduce, the faulty DNA will be copied during gametogenesis and will appear in a predictable percentage of offspring. Section Title: Metabolism Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 120) Explain how enzymes can be useful in the diagnosis of disease, giving specific examples. Is the change in enzyme concentration a direct or indirect result of the disease?

: Many enzymes are normally present in the blood in a particular range of concentrations. Alterations in these concentrations can be associated with abnormal conditions. For example, elevation in the digestive enzyme amylase, produced by the pancreas, may indicate pancreatic disease. Elevation of enzymes that normally operate inside cells can indicate tissue damage, such as the elevation of creatine kinase following myocardial infarction. Low amounts of hexosamidase A can indicate Tay-Sachs disease. In the examples given, the amylase and hexosamidase enzyme changes are direct results of the disease, whereas enzymes elevated because of tissue damage are the result of cellular damage and not a direct change in the enzyme itself. Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 73) ________ generated in the ________ enter the electron transport system to generate 2.5 ATP molecules.

: NADH, mitochondria Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 121) Based on the facts about chemical equilibria in animal systems, indicate for each summary reaction below if it is reversible or irreversible (don't worry about balancing the reactions). Explain the lack of reversibility. In what kind of system would the reaction(s) you selected as irreversible be reversible? Explain. A. C6H12O6 → CO2 + H2O B. ADP + Pi → ATP C. H2O + CO2 → H2CO3

: Only A is irreversible in animal systems. The products are rapidly removed from the system as soon as they are formed, so they are not recombined. This reaction is reversible in plants, which form and store glucose for food, but also need to use some of the glucose to make ATP. Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 117) Explain how these statements differ, and identify which one(s) is/are correct. Explain what is wrong with each incorrect statement. A. A chemical reaction is at equilibrium when there is no further change in substrates. B. A chemical reaction is at equilibrium when the amounts of substrates and product no longer change. C. A chemical reaction stops when it reaches equilibrium. D. A chemical reaction is at equilibrium when the amount of substrate equals the amount of product.

: Only B is correct as written. A could be corrected by clarifying that it is concentration or amount of substrate that ceases to change; individual molecules can form or break at any given time, but the overall amount will not change because synthesis will be balanced by degradation. C is incorrect because the reactions continue as long as conditions such as presence of catalysts, favorable temperature, and presence of substrates are maintained. As a given enzyme can both synthesize and degrade, both processes will continue even at equilibrium. D is incorrect because at equilibrium there is no net change in amounts, but it is not necessary for concentrations of substrates and products to be the same as each other. Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 116) Briefly describe oxidation-reduction reactions. What does it mean for a molecule to be reduced or oxidized? Identify and explain the mnemonic device provided in the text for oxidation and reduction reactions. See if you can make one up yourself.

: Oxidation-reduction reactions occur when electrons are transferred from one molecule to another. The molecule that is oxidized in the reaction loses electrons while the reduced molecule gains electrons. OIL RIG (oxidation is loss, reduction is gain) is the mnemonic provided in the textbook. Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 93) Describe the four types of enzymatic reactions.

: Oxidation-reduction reactions transfer electrons or protons between substrates. Hydrolysis-dehydration reactions form or break a chemical bond between organic substrates by removing or adding a water molecule. Transfer reactions (Addition-subtraction-exchange reactions) add, remove, or exchange a functional group (phosphate or amino groups) among the substrates. Ligation reactions join molecules using the energy from an ATP molecule. Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 90) Compare and contrast potential energy with kinetic energy.

: Potential energy is the energy an object has stored in its position, while kinetic energy is energy associated with a moving object/movement. Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 131) Once the promoter region of a gene is activated, ________ unwinds the DNA of the downstream gene and begins the process of ________. What is the molecule generated by this process? How does the cell control the amount of this molecule released from the nucleus?

: RNA polymerase, transcription The RNA polymerase transcribes a single stranded mRNA. The cell can decrease mRNA by controlling the activity of the promoter with transcription factors if the gene is not constitutively expressed. Decreases in an inducer or increases in a repressor would reduce the amount of mRNA available for release. In addition, the amount of mRNA released is also affected by the availability of interfering RNA (siRNA or miRNA). Increases in interfering RNA that can inactivate or destroy mRNA would reduce the amount of mRNA released from the nucleus. Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 68) ________ describes how much product is generated or substrate destroyed within a period of time.

: Reaction rate Section Title: Chemical Reactions Learning Outcome: 4.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 133) How is the single-stranded mRNA that leaves the nucleus translated into proteins?

: Ribosomes have two subunits (large and small) that are composed of proteins and rRNA. The small subunits binds to the mRNA followed by the large subunit which sandwiches the mRNA. The tRNA (contains the anticodon and associated amino acid) binds to the complementary mRNA. A second tRNA arrives for the next codon and, via dehydration synthesis, a peptide bond is formed between amino acids, which releases the first tRNA from the mRNA and allows the next tRNA to bind. This process continues until the stop codon is reached. Section Title: Metabolism Learning Outcome: 4.6

: Level III: Problem Solving (Bloom's Taxonomy: Evaluation) 140) Create a map that integrates the following terms: alternative splicing, constitutive, interference, mRNA, post-translation modification, regulated, repression, induction, translation, and tRNA. Add terms as needed.

: See Figure 4.18 through 4.21 in the chapter. Section Title: Metabolism Learning Outcome: 4.6

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 141) Draw a graph of the free energy of a molecule as a function of time for an exergonic reaction and endergonic reaction. Label on the graph "activation energy" and "net free energy change." How would these reactions be altered by the presence of an enzyme for this reaction?

: See Figure 4.3 in the chapter. The activation energy would be reduced which would increase the rate of these reactions. Section Title: Enzymes Learning Outcome: 4.2

: Level IV: Quantitative Problems (Bloom's Taxonomy: Application) 142) Graph the effects of changing pH on enzyme activity. In humans, what is the pH for optimal activity of most enzymes?

: See Figure 4.6 in the chapter. The optimal pH for most enzymes is 7.4. Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 135) Define substrate and product. Are these definitions relative or absolute, and why?

: Substrates are chemicals that bind to the enzyme and are altered (bonds formed and/or broken), producing a product. A product is the result of enzyme action on substrates. These terms are relative because chemical reactions are reversible. Example: if two monomers bind to the enzyme and form a dimer, the monomers are the substrates and the dimer is the product. If instead the dimer binds to the enzyme and splits to form two monomers, the monomers are the products and the dimer is the substrate. Section Title: Enzymes Learning Outcome: 4.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 132) Once the mRNA for a particular gene has been transcribed, how is the mRNA that will be released from the nucleus processed?

: The mRNA that is initially transcribed contains regions that are not part of the protein that will be translated. These noncoding regions of mRNA (introns) are removed from the mRNA by splicing. The mRNA then only contains the coding sequences (exons) that can be released from the nucleus to be translated by the ribosome. Due to alternative splicing, the structure of the protein can be different which leads to isoforms of a protein. Section Title: Metabolism Learning Outcome: 4.6

: Level IV: Quantitative Problems (Bloom's Taxonomy: Synthesis) 145) Carbon dioxide and water readily combine to form carbonic acid. The change in pH as the acid dissociates can be demonstrated with an indicator dye that changes color at a particular pH. Following this lab in which the color of the solution was observed to change, one lab group forgot to dump the beakers at the end of the lab period. The next day would you expect the beakers to look the same as they did after being bubbled with CO2? If not, explain in terms of reversible reactions and equilibrium disturbance.

: The next day, the solutions had changed back to their original color (before being bubbled with CO2). The carbon dioxide dissipated over night, driving the reaction back in the reverse direction, because the amount of substrate changed. This caused the pH to increase again, above the level required to maintain the color change. Section Title: Enzymes Learning Outcome: 4.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 126) After coming off a ribosome, several things can happen to the newly synthesized protein. Name three.

: The possible answers include the post-translational modifications: 1. folded into three-dimensional shapes 2. cross-linkages (disulfide bonds) between different regions of its amino acid chain 3. be cleaved into fragments 4. attach other molecules or groups (e.g., methylation) 5. assemble with other peptides (subunits) into polymeric proteins Section Title: Metabolism Learning Outcome: 4.6

: Level IV: Quantitative Problems (Bloom's Taxonomy: Synthesis) 147) Analysis of a single DNA strand yielded this information on amounts of some nucleotides: 43 units of cytosine and 51 units of adenine. What amounts would you expect of guanine and thymine in that strand? What amounts would you expect of all bases in the complementary strand?

: There is no way to determine the amounts of guanine and thymine in the analyzed strand based on the amounts of cytosine and adenine; the guanine and thymine would have to be determined directly. In the other strand, the amount of guanine equals the amount of cytosine in the analyzed strand, and the amount of thymine equals the amount of adenine in the analyzed strand, because of the way the bases pair to hold the strands together. Once the amounts of guanine and thymine in the first strand are determined, the amounts of cytosine and adenine can be determined in the complementary strand. Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 91) Define the law of mass action.

: When a reaction is at equilibrium, the ratio of the substrates to the products is always the same because reaction rate is constant. Section Title: Enzymes Learning Outcome: 4.2

: Level IV: Quantitative Problems (Bloom's Taxonomy: Application) 144) Carbon dioxide and water readily combine to form carbonic acid. The change in pH as the acid dissociates can be demonstrated with an indicator dye that changes color at a particular pH. In your physiology lab, you perform this experiment in two beakers containing room-temperature water and indicator, labeled Resting and Exercise based upon the status of the student who exhaled through a straw into the solution. The Resting student had been sitting at the table for 30 minutes before exhaling while the Exercise student had just finished sprinting up the stairs to class late. A stopwatch was used to measure how long it took for the solutions to change color. The following data were generated by the students. Explain why the time required for the color to change was different between groups, using the word substrate in your answer. Student Time for reaction (seconds): Resting Time for reaction (seconds): Exercising 1 123 20 2 114 23 3 136 17

: With each breath, CO2 is present in the exhaled air. The students who exercised exhibited an elevated rate of CO2 generation by the metabolic cycle. Thus, the substrate concentration was higher for the Exercising student than the Resting student, which is why the time for the solution to change color was less. Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 76) During the synthesis of proteins, amino acids are assembled in the proper sequence because the tRNA molecules that bring them to the ribosome have a(n) ________ that is complementary to a specific codon in the mRNA.

: anticodon Section Title: Metabolism Learning Outcome: 4.6

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 130) Vitamins are precursors for ________. Name two vitamins that are required for metabolic reactions.

: coenzymes Vitamins required for metabolic reactions include the B vitamins such as folic acid, biotin, and pantothenic acid and vitamin C. Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 84) Genes that are always being expressed in a cell involve promoters that are ________.

: constitutively active Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 65) Metabolic intermediates use ________ bonds to transfer energy to the high-energy bonds of ATP, NADH, FADH2 or NADPH.

: covalent Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 88) The peptide bond formed between amino acids occurs as a consequence of ________.

: dehydration synthesis Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 63) Chemical reactions that require an input of energy are said to be ________.

: endergonic Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 66) The rates of chemical reactions that occur in the human body are controlled by a particular type of proteins called ________.

: enzymes Section Title: Enzymes Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 64) Chemical reactions that release energy are said to be ________.

: exergonic Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 87) The ________ is the portion of the mRNA that contains the coding sequence of the gene.

: exon Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 86) The ________ contains the coding sequence of the gene.

: exon Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 70) Glucose is phosphorylated to ________ with a phosphate from ________.

: glucose-6-phosphate, ATP Section Title: Metabolism Learning Outcome: 4.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 134) The folding of proteins occurs via the formation of weak ________ and ________ bonds between amino acids. Much stronger covalent bonds like ________ bonds can occur between ________ amino acids.

: hydrogen, ionic, disulfide, cysteine Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 75) The electron transport system is located in the ________ and includes enzymes and iron-containing proteins known as ________.

: inner mitochondrial membrane, cytochromes Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 67) A certain molecule that participates in more than one biochemical pathway and acts as a branch point for channeling substrate in one direction or another is called a ________.

: key intermediate Section Title: Metabolism Learning Outcome: 4.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 80) A molecule of ________ consists of all the codons needed to produce a specific polypeptide chain at the ribosome.

: mRNA Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 89) Protein folding can take place spontaneously or with ________.

: molecular chaperones Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 69) The availability of ________ determines if pyruvate continues into the citric acid cycle.

: oxygen Section Title: Metabolism Learning Outcome: 4.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 72) In the process of ________ a phosphate group is attached to a molecule.

: phosphorylation Section Title: Enzymes Learning Outcome: 4.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 61) A molecule positioned on the high-concentration side of a concentration gradient stores ________ energy.

: potential Section Title: Energy in Biological Systems Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 74) Energy released by electrons moving through the electron transport system is stored as ________ by H+ ions concentrated in the ________.

: potential energy, intermembrane space Section Title: Metabolism Learning Outcome: 4.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 85) Transcription factors are proteins whose binding to the ________ region for a gene can ________ (increase) or ________ (decrease) expression of that gene.

: promoter, induce, repress Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 81) Ribosomes are composed of protein and ________.

: rRNA Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 62) A chemical reaction that can proceed in both directions is called a ________.

: reversible reaction Section Title: Chemical Reactions Learning Outcome: 4.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 82) RNA is usually ________ -stranded.

: single Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 83) Two types of RNA block translation of mRNA. They are ________ RNA and ________ RNA.

: small interfering, micro Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 78) Amino acids are carried to the ribosomes to be incorporated into polypeptide chains by ________.

: tRNA Section Title: Metabolism Learning Outcome: 4.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 77) mRNA is created in a process called ________. It then leaves the ________ and enters the cytosol to direct ________, the assembly of amino acids into protein.

: transcription; nucleus, translation Section Title: Metabolism Learning Outcome: 4.6