BIO 305 Exam | Questions and Answers (Complete Solutions)

BIO 305 Exam | Questions and Answers (Complete Solutions) Anabolic pathways usually involve ____. a. Reduction of Metabolites b. Release of PPi c. Production of ATP d Release of CO2 Diffusion of compounds - e.g. ions, ...

BIO 305 Exam | Questions and Answers (Complete Solutions) Anabolic pathways usually involve ____. a. Reduction of Metabolites b. Release of PPi c. Production of ATP d Release of CO2 Diffusion of compounds - e.g. ions, atoms, or molecules - down a gradient is ___ because it ___. a. Endergonic; does not involve bond formation. b. Exergonic; produces heat. c. Exergonic; increases entropy. d. Exergonic; separates like charges _____is a high energy compound because its hydrolysis involves conversion of a thioester with poor pi overlap into an oxygen ester, which has good pi overlap. a. Pyruvate b. Acetyl CoA c. NADH d. FADH2 Conversion of NADH to NAD+ is ___ because it ___. a. Exergonic; separates like charges. b. Exergonic; increases the number of polar bonds. c. Exergonic; is driven forward by LeChatelier's Principle. d. Exergonic; increases charge delocalization. A net product of catabolism is a. NADH b. sugar, e.g. glucose c. PPi d. ATP In the absence of O2, glucose is converted to ___ in glycolysis and then __ during fermentation: a. Pyruvate; Acetyl CoA b. G3P; Acetyl CoA c. Acetyl CoA; Citric acid d. Pyruvate; Lactate or ethanol and CO2 Which of the following is an anabolic (anabolism) pathway? a. Gluconeogenesis b. Glycolysis c. Pyruvate Dehydrogenation (PDH) d. Beta-oxidation of fatty acids A metabolite common to oxidation of both glucose and fatty acids is: a. DHAP b. Acetyl CoA c. G3P d. Pyruvate Reactions in which either CO2 or PPi are produced tend to be very exergonic because: a. Their concentrations quickly decrease, driving the reactions forward due to LeChatelier's Principle. b. The bond energies of the products are much lower than those of the reactants. c. Reactions coupled to their production involve reduction of the metabolite. d. Reactions coupled to their production involve oxidation of the metabolite. In the presence of O2, glucose is converted to ___ during glycolysis and then __ in order to be used in the Citric Acid Cycle: a. Pyruvate; Citric Acid b. Pyruvate; Acetyl CoA c. G3P; pyruvate d. Acetyl CoA; CoA Which of these is associated with production of ATP during glycolysis? a. Conversion of PEP to Pyruvate b. Phosphorylation of glucose c. Conversion of DHAP to G3P d. Conversion of 2,3 BPG to PG Which of these reactions is associated with production of NADH during glycolysis? (Select all that apply) a. DHAP --> G3P b. G3P --> 1,3BPG c. PEP--> Pyruvate d. 1,3 BPG --> 3 PG The reaction converting Glucose-6-phosphate to Fructose-6-phosphate is catalyzed by a/an _____. a. Kinase b. Dehydrogenase c. Dehydratase d. Isomerase Conversion of 3-phosphoglycerate to 2-phosphoglycerate is catalyzed by a/an: a. Dehydratase b. Isomerase c. Phosphorylase d. Kinase Glycolysis occurs in the a. Cytoplasm. b. Endoplasmic Reticulum c. Inner mitochondrial membrane d. Mitochondrial Matrix The first half of glycolysis is called investment phase or preparatory phase because a. ATP is released to form a nearly symmetrical molecule. b. ATP is released to trap glucose in the cell. c. ATP is consumed to form G3P at the end of this phase d. ATP is consumed to generate NADH at the end of this phase Which of these reactions occurs during glycolysis? (Note that only the major metabolites are shown) a. Fructose-6-P -> Fructose-1,6-BP b. Fructose -> Fructose-6-P c. Fructose-6-P -> Glucose-6-P d. Fructose-1-P -> Fructose-6-P Conversion of 2PG to PEP is catalyzed by a/an: a. Dehydratase b. Isomerase c. Phosphorylase d. Kinase Which of the following reactions occurs during glycolysis? (Note that only the major metabolites are shown) a. Fructose + ATP -> Fructose-6-P + ADP b. Fructose + Pi -> Fructose-6-P c. Glucose + Pi -> Glucose-6-P d. Glucose + ATP -> Glucose-6-P + ADP Number of reactions/steps that are highly regulated during glycolysis is/are_____. a. 10 b. 3 c. 1 d. 4 Which of the following would be expected to be, if anything, an inhibitor glycolysis? a. Pyruvate b. NAD+ c. Glucose d. ADP Phosphofructokinase (PFK-1) is ____ when ATP levels are low, and ____ when ATP levels are high. a. Inhibited; activated b. Activated; inhibited c. Activated; activated d. Inhibited; inhibited All reactions that involve dephosphorylation of a biological molecule are favorable due to: a. Separation of like charges b. All options are correct c. Delocalization of electrons d. Le Chatelier's Principle Which of these processes is most exergonic? (Think VERY carefully!) a. Oxidation of an aldehyde to a carboxylic acid group. b. Dephosphorylation of glucose c. ATP hydrolysis d. Conversion of enol to keto The breakdown of many digestible sugars converges on metabolism at the glycolytic intermediate _______. Therefore, glycolysis can still take place even when hexokinase has been inhibited a Fructose-6-phosphate b. G3P c. DHAP d. Glucose-6-Phosphate Which of the following factors does not pay for the generation of NADH and ATP during steps 6 and 7 of glycolysis? a. Oxidation of an alcohol group to an aldehyde group b. Enthalpy c. Solvation d. Delocailization of electrons/Resonance Which of the following reactions is the most exergonic? a. All of the reactions are equally exergonic. b. Hydrolysis of ATP c. Conversion of PEP to Pyruvate d. Conversion of Glucose-6-phosphate to Glucose Many sugars, including galactose, fructose, and mannose, are converted into ______ to be catabolized in glycolysis. a. Fructose-6-Phosphate b. Glucose-6-Phosphate c. Glucose d. Acetyl-CoA The most regulated enzyme in glycolysis is a. Hexokinase b. Phosphofructokinase c. Pyruvate Kinase d. G3P Dehydrogenase Which of the following is not a net product (i.e. of both phases) of the pentose phosphate shunt? a. CO2 b. NADPH c. NADH d. Ribose-5-P Which of the following is water-soluble and therefore must bind to a cell surface receptor in order to elicit a cellular response? a. Estradiol b. Aldosterone c. Glucagon d. Testosterone Which of the following is NOT produced during the oxidative phase of the pentose phosphate shunt? a. NADPH b. Ribulose-5-Phosphate c. CO2 d. Glyceraldehyde-3-phosphate The pentose phosphate pathway: a. Involves carboxylation followed by decarboxylation of a metabolite. b. Produces NADPH for use in fatty acid synthesis. c. Produces heat through simultaneous activation of both catabolic and anabolic reactions. d. Produces glucose from pyruvate. Which of the following is NOT one of the products of the pentose phosphate shunt? a. CO2 b. Ribose-5-Phosphate c. NADPH d. ATP Which of the following is water-soluble and therefore must bind to a cell surface receptor in order to elicit a cellular response? a. Epinephrine b. Aldosterone c. Estradiol d. Testosterone Which of the following reactants is common to the pentose phosphate pathway and glycogen synthesis? a. Glucose-6-Phosphate b. ADP c. Glucose-1-Phosphate d. NADH The pathway leading to glycogen synthesis involves all EXCEPT which of the following compounds? a. Glucose-1-P b. Fructose-1,6-BP c. Glucose-6-P d. UTP Glycogen breakdown requires: a. inorganic phosphate b. HCO3- c. UTP d. ATP The pentose phosphate shunt is likely to be active when: a. fatty acid beta-oxidation is active. b. an organism is growing c. the organism has not had a meal for a long time. d. AMP levels are high The Bypass reactions of gluconeogenesis: a. Make conversion of pyruvate to glucose possible without using ATP. b. Reverses glycolysis reactions that are very exergonic. c. Provide both reducing power in the form of NADPH and nucleic acid building blocks using intermediates of glycolysis. d. Evolved to generate heat. Two of the bypass reactions of gluconeogenesis involve: a. phosphorylation of ADP using phosphate from the metabolite. b. phosphorylation of the metabolite using phosphate from Pi. c. phosphorylation of the metabolite using phosphate from ATP. d. dephosphorylation of the metabolite without using it to make ATP. Bypass I of gluconeogenesis requires a source of energy. This energy comes from: a. 2 ATP b. oxidation of the metabolite c. 1 ATP + 1 NADH d. 6 ATP Which of the following types of enzymes/reactions is used in one or more bypass reactions of gluconeogenesis but is not used in glycolysis? a. Carboxylase b. Phosphorylase c. Dehydrogenase d. Mutase For every molecule of glucose produced, gluconeogenesis consumes: a. 4 ATP and 1 NADH b. 6 ATP and 2 NADH c. 4 ATP and 0 NADH d. 2 ATP and 2 NADH Which of the following statements regarding gluconeogenesis is NOT true: a. It involves one or more intermediates that are different from those of glycolysis. b. It results in production of glucose from pyruvate. c. It utilizes all of the same enzymes as glycolysis. d. It consumes ATP. The reaction Glucose-6-P --> Glucose + Pi occurs in Bypass ___ of gluconeogenesis and is catalyzed by a ____: a. III; phosphorylase b. I; phosphorylase c. III; phosphatase d. I; phosphatase A single futile cycle, i.e. one round of glycolysis plus one round of gluconeogenesis consumes: a. 6 ATP; 2 NADH b. 2 ATP; 1 NADH c. 4 ATP; 0 NADH d. 4 ATP; 4 NADH Epinephrine acting on liver cells causes enzymes involved in glycogen metabolism to become ____ and, therefore ____. (Caution: Think Carefully!!!!) a. Phosphorylated; Active b. Dephosphorylated; either active or inactive, depending on the enzyme c. Dephosphorylated; Inactive d. Phosphorylated; either active or inactive, depending on the enzyme Insulin signaling results in activation of ____ in liver cells resulting in ____. a. protein kinase a, glycogen synthesis