Exam 3 (Part 1) Questions PDF

Which hormone primarily promotes glycogen synthesis? A\) Insulin B\) Cortisol C\) Glucagon D\) Epinephrine Which enzyme converts glucose 6-phosphate to glucose 1-phosphate? A\) Lactate dehydrogenase B\) Hexokinase C\) UDP-glucose pyrophosphorylase D\) Phosphoglucomutase Which vitamin is NO...

Which hormone primarily promotes glycogen synthesis? A\) Insulin B\) Cortisol C\) Glucagon D\) Epinephrine Which enzyme converts glucose 6-phosphate to glucose 1-phosphate? A\) Lactate dehydrogenase B\) Hexokinase C\) UDP-glucose pyrophosphorylase D\) Phosphoglucomutase Which vitamin is NOT a coenzyme involved in the PDH complex? A\) Thiamine (TPP) B\) Pantothenate (CoA) C\) Vitamin C D\) Riboflavin (FAD) Which of the following reactions in the citric acid cycle produces FADH2? A\) Decarboxylation of α-ketoglutarate B\) Oxidation of malate to oxaloacetate C\) Oxidation of succinate to fumarate D\) Hydration of fumarate Which of the following is a unique characteristic of ketone bodies? A\) They are produced exclusively in adipose tissue B\) They are directly derived from amino acids C\) They can cross the blood-brain barrier D\) They are synthesized from carbohydrates What is a key function of bile salts in the processing of dietary lipids? A\) They transport lipids directly to liver cells. B\) They emulsify dietary lipids in the intestine. C\) They break down lipids into free fatty acids. D\) They enhance the storage of triglycerides in adipose tissue. Which hormone is responsible for stimulating the release of bicarbonate from the pancreas? A\) Secretin B\) Enteropeptidase C\) Cholecystokinin D\) Gastrin What is the role of Complex II in the electron transport chain? A\) It synthesizes ATP directly from succinate oxidation. B\) It transports electrons to molecular oxygen. C\) It pumps protons across the membrane. D\) It couples the oxidation of succinate with the reduction of ubiquinone. What is the main role of the inner mitochondrial membrane? A\) Regulating the transport of specific molecules and ions B\) Facilitating the passage of all small ions and molecules C\) Housing the enzymes for glycolysis D\) Acting solely as a barrier for the outer membrane What are hormones primarily produced and released from? A\) Receptors B\) Tissues C\) Nerve cells D\) Bloodstream A doctor sees a patient with a genetic mutation affecting citrate synthase. The patient has symptoms of fatigue and low ATP production. Which of the following best explains the impact of this mutation? A\) The citric acid cycle cannot proceed because oxaloacetate cannot react with acetyl-CoA to form citrate. B\) The electron transport chain is unaffected because citrate is not required for NADH production. C\) Glycolysis compensates completely for the reduced ATP production by the citric acid cycle. D\) Fatty acid metabolism increases to compensate for the reduced citrate production. A patient with a metabolic defect has trouble converting succinate to fumarate in the citric acid cycle. Which enzyme is malfunctioning? A\) An enzyme that catalyzes the isomerization of citrate to isocitrate via cis-aconitate. B\) An enzyme that catalyzes the oxidative decarboxylation of α-ketoglutarate to succinyl-CoA, producing NADH. C\) An enzyme that is used in Complex II to oxidize succinate to fumarate while transferring electrons to ubiquinone (CoQ). D\) An enzyme that catalyzes the conversion of malate to oxaloacetate, generating NADH. A patient with a mitochondrial disease affecting Complex IV experiences extreme fatigue. Which of the following best explains why ATP production is reduced? A\) NADH cannot transfer electrons to the electron transport chain, disrupting the proton gradient. B\) Complex IV cannot reduce oxygen to water, causing the proton gradient to collapse. C\) ATP synthase is unable to function due to a lack of ubiquinone. D\) Electrons bypass Complex IV and directly produce ATP. A patient with a mitochondrial disorder experiences muscle weakness and fatigue. Tests show a defect in Complex III of the electron transport chain. The doctor explains that this defect reduces ATP production. Which of the following best describes why ATP production is impaired? A\) Electrons from NADH cannot reach oxygen, preventing proton pumping and creating a low ΔG across the inner mitochondrial membrane. B\) Complex III cannot oxidize NADH, resulting in an inability to produce acetyl-CoA for the citric acid cycle. C\) Oxygen is unable to bind to Complex III, preventing ATP synthase from functioning. D\) The mutation reduces substrate-level phosphorylation in the citric acid cycle. A patient with uncontrolled diabetes is experiencing high levels of ketones in the blood. If a 16-carbon fatty acid undergoes beta-oxidation and enters the citric acid cycle, how many NADH molecules are produced in total? A\) 23 B\) 31 C\) 35 D\) 48 A fasting patient has elevated levels of glycerol in their blood. The doctor explains that glycerol is converted into a glycolytic intermediate. Which enzyme catalyzes the first step in this conversion? A\) Glycerol Kinase B\) Pyruvate Carboxylase C\) Hexokinase D\) Glucose-6-Phosphatase. A patient with hyperammonemia is diagnosed with a defect in the urea cycle. The doctor explains that the urea cycle primarily occurs in which of the following organs? A\) Brain B\) Kidneys C\) Liver D\) Pancreas A patient is experiencing hypoglycemia (low blood sugar levels) during fasting. Their physician explains that glycogen is broken down to maintain blood glucose levels. Which enzyme is responsible for initiating this process? A\) Glycogen Synthase B\) Glycogen Phosphorylase C\) Glucose-6-Phosphatase D\) Pyruvate Kinase A patient with insulin resistance has elevated blood glucose levels. The doctor explains that insulin normally binds to its receptor to trigger glucose uptake. Which of the following best describes the receptor involved in this process? A\) G-protein coupled receptor (GPCR) B\) Tyrosine kinase receptor C\) Nuclear receptor D\) Ligand-gated ion channel 10.A patient shows signs of elevated blood glucose and triglycerides levels. Which of the following hormonal imbalances is most likely contributing to their condition? A\) Increased glucagon and decreased insulin activity B\) Decreased glucagon and increased insulin activity C\) Decreased epinephrine and increased insulin sensitivity D\) Increased insulin sensitivity and decreased cortisol levels PDH complex activity is regulated by everything EXCEPT: A. Fatty acid prevalence B. \[ATP\]/\[ADP\] Ratios C. \[NADH\]/\[NAD+\] Ratios D. Zn 2+ E. Ca 2+ Which of the following enzymes is linked to the reduction of NADH? A. Pyruvate dehydrogenase B. Aconitase C. Malate dehydrogenase D. Succinyl-CoA Synthase E. Succinate dehydrogenase Which electron carrying molecule in the respiratory chain does this heme group belong to? A. Ubiquinone B. Coenzyme Q C. A-type cytochrome D. B-Type Cytochrome E. C-type Cytochrome The enzyme \_\_\_\_\_\_ from the citric acid cycle also "moonlights" as complex \_\_\_ in the electron transport chain A. Aconitase, I B. Succinate dehydrogenase, III C. Succinate dehydrogenase, II D. Cytochrome oxidase, IV E. ATP synthase, III Lipoprotein lipase, activated by \_\_\_\_\_ in the \_\_\_\_\_\_\_ converts triacylglycerols to fatty acids and monoacylglycerols. A. apoC-II, capillary B. apoB-48, capillary C. apoC-II, small intestine D. aopB-48, adipocyte E. Serum albumin, bloodstream A person severely lacking biotin could exhibit signs of which disease? A. Fatty Liver disease B. Propionic Acidemia C. Zellweger Syndrome D. X-linked adrenoleukodystrophy (XALD) E. Diabetes Vigorous muscle activity triggers which enzyme first? A. Glycogen Phosphorylase a B. Glycogen Phosphorylase b C. Phosphorylase b kinase D. PKA E. Adenylyl cyclase The Glycogenin mechanism begins with formation of a glycosidic bond between the glucose of UDP-glucose and \_\_\_\_ of glycogenin A. Tyr B. His C. Lys D. Trp E. Phe Trypsin activates which zymogens? A. Trypsinogen B. Precarboxypeptidases A and B C. Enteropeptidase D. A and B E. B and C Which of the following about beige adipocytes is FALSE? A. Can only be converted by cold exposure B. Have multiple lipid droplets C. Are richer in mitochondria than white adipocytes D. Produce UCP1 E. They are very similar to brown adipocytes Which of the following is the purpose of phosphoglucomutase is glycogenolysis? a\. To catalyze the phosphorolytic cleavage of glycogen to glucose-1-phosphate b\. To convert glucose-6-phosphate to glucose in the liver so that it can be used in other processes other than glycolysis c\. To convert glucose-1-phosphate to glucose-6-phosphate so that it could be used in muscle and liver cells d\. To remove branches of glycogen so that the glycogen phosphorylase can continue working Which of the following nucleotides is used to commit a glucose molecule to glycogen synthesis? a\. ADP b\. AMP c\. UTP d\. GTP What is the effect of ATP on PDH and the citric acid cycle? a\. ATP allosterically inhibits PDH kinase, allowing PDF to continue functioning and the citric acid cycle to continue b\. ATP allosterically activates PDH kinase, inhibiting the enzyme and the citric acid cycle c\. ATP has no effect on PDH or the citric acid cycle d\. ATP activates PDH phosphatase, activating PDH and the citric acid cycle Which of the following is not a coenzyme used in the citric acid cycle? a\. B6 b\. Lipoate c\. Coenzyme A d\. Flavin adenine dinucleotide (FAD) Where are ketone bodies created in the body? a\. Kidney b\. Muscle cells c\. Liver d\. Intestine If you were following a fatty acid destined for oxidation in the mitochondria, what molecule would you find on the inner side of the mitochondrial membrane (towards the matrix)? a\. Carnitine cotransporter b\. Carnitine acyltransferase 2 (CAT2) c\. Carnitine acyltransferase 1 (CAT1) d\. Carnitine shuttle Which of the following is a key amino acid for amino acid oxidation? a\. Histidine b\. Glutamate c\. Proline d\. Glycine What is the purpose of Complex I in oxidative phosphorylation? a\. It is a proton pump b\. To create NADH c\. To create FADH d\. To synthesize cytochromes What is the purpose of heme b in Complex II? a\. To assist in substrate channeling b\. To catch free radicals made by the complex c\. To assist in pumping protons d\. To synthesize NADH Which of the following is found in the liver? I. Epinephrine II\. Insulin III\. Glucagon a\. I and II b\. Only I c\. III and II d\. I, II and III How does glucose-6-phosphate inhibit hexokinase? A. By competitive inhibition, directly binding to the active site of hexokinase. B. By allosteric feedback inhibition, binding to a site other than the active site. C. By reducing the availability of ATP required for hexokinase activity. D. By increasing the affinity of hexokinase for glucose. When our muscles contract, what accumulates, and how does it speed up glycogen breakdown? A. ATP accumulates, blocking the allosteric site, which inactivates phosphorylase. B. AMP accumulates and binds to phosphorylase, activating it. C. Ca²⁺ accumulates, binding and deactivating phosphorylase b kinase. D. Glucagon accumulates and binds to inactive PKA, activating it and accelerating activity. In muscles, which two molecules act as allosteric activators of glycogen phosphorylase? A. Mn²⁺ and ATP B. Ca²⁺ and AMP C. Fructose-2,6-bisphosphate and Citrate D. AMP and Glucose In the conversion of pyruvate to acetyl-CoA, how does pyruvate dehydrogenase use lipoate to facilitate the formation of acetyl-CoA? A. It removes carbon from pyruvate in the form of CO₂ B. It transitions from reduced to oxidized to receive the hydroxyethyl group from TPP C. It transitions from oxidized to reduced, opening the disulfide bridge to accept the hydroxyethyl group from TPP D. It reduces FAD⁺ to allow CoA to attach to the hydroxyethyl group Which steps of the citric acid cycle produce CO₂ as a byproduct? A. The conversion of citrate to isocitrate and the conversion of succinate to fumarate B. The conversion of isocitrate to α-ketoglutarate and the conversion of α-ketoglutarate to succinyl-CoA C. The conversion of succinyl-CoA to succinate and the conversion of malate to oxaloacetate D. The conversion of fumarate to malate and the conversion of citrate to isocitrate In the mobilization of triacylglycerols, what would happen if the ATGL enzyme were mutated and became non-functional? A. The lipid droplet would not open because ATGL cannot be phosphorylated. B. ATGL would fail to be activated by CGI-58 and could not break down triacylglycerol to diacylglycerol. C. ATGL would be unable to phosphorylate itself and break down diacylglycerol into monoacylglycerol. D. ATGL would no longer accept free fatty acids for transport through the bloodstream. How do fatty acids enter the mitochondrial membrane for β-oxidation? A. Via palmitoyl-CoA transferase B. Using the citrate shuttle C. Via the malate shuttle D. Bound to serum albumin When alanine enters the liver, how does it contribute to urea production? A. By using alanine aminotransferase to transfer its amino group to α-ketoglutarate, forming glutamate. B. By directly converting into pyruvate, releasing NH₄⁺ for urea synthesis. C. By using α-ketoglutarate to convert it back to pyruvate, releasing NH₄⁺. D. By converting α-ketoglutarate to glutamate, which directly enters the urea cycle. What allows for the release of ATP in ATP synthase A. The binding of ADP and inorganic phosphate (Pi) to the active site. B. The proton gradient drives conformational changes in the enzyme. C. The hydrolysis of ATP to ADP and Pi within the enzyme. D. The movement of electrons through the electron transport chain. What is the primary role of Complex III in the electron transport chain of oxidative phosphorylation? A. To oxidize FADH₂ and directly produce ATP. B. To transfer electrons from ubiquinol (QH₂) to cytochrome c and pump protons into the intermembrane space. C. To reduce oxygen to water while generating a proton gradient. D. To transfer electrons from NADH to ubiquinone (Q) and produce NAD⁺. How is preproinsulin processed into mature insulin? A. By the removal of disulfide bonds and cleavage of the A chain B. By folding into its active conformation and adding phosphate groups C. By cleavage of the signal peptide, formation of disulfide bonds, and removal of the C-peptide D. By adding glucose molecules to the B chain and cleaving the A chain Which of the following statements accurately describes key metabolic pathways and their regulation? A. Glycolysis is regulated primarily at hexokinase, which is inhibited by high levels of ATP, while pyruvate dehydrogenase is activated by NADH B. The citric acid cycle is a linear pathway in the cytoplasm, regulated by isocitrate dehydrogenase, which is stimulated by ATP C. The pentose phosphate pathway produces NADPH and ribose-5-phosphate, and its oxidative phase is regulated by the availability of NADP⁺ D. In fatty acid metabolism, β-oxidation occurs in the cytoplasm and is regulated by acetyl-CoA carboxylase, which is stimulated by glucagon Consider the way that glycogen is stored within a cell. Which answer choice correctly ranks the glycogen storage particles from smallest to largest? a\) Glucose, α-granule, β-granule b\) α-granule, β-granule, glucose c\) Glucose, β-granule, α-granule d\) β-granule, α-granule, glucose Glycogenolysis releases a form of glucose that cannot enter glycolysis. What enzyme can transform it into a glycolytic intermediate? a\) Glycogen phosphorylase b\) Phosphoglucomutase c\) NDP-sugar pyrophosphorylase d\) Glycogenin In glycogenolysis, why is the glucose 6-phosphatase activity in the ER lumen? a\) Glycogenolysis occurs in the ER lumen b\) It prevents the futile cycle with enzymes of the glycolytic pathway c\) The first steps of glycolysis are in the ER lumen d\) It allows glucose to be easily exported from the liver by GLUT2 e\) It allows lipogenesis to occur rapidly A patient was seen by a gastrointestinal specialist and diagnosed with a glycogen storage disease. A liver biopsy showed that the patient was producing very little glycogen, the molecules were relatively small, and they only had α(1→4) glycosidic linkages. Blood and liver glucose concentrations were within normal ranges. What enzyme is LIKELY affected in this disease? a\) Glycogen synthase b\) Hexokinase c\) Glycosyl (4→6) transferase d\) Glycogenin e\) UDP-glucose pyrophosphorylase Which nucleotide is required for glycogen synthesis? a\) ATP b\) UTP c\) CTP d\) GTP e\) cAMP Glycogenesis a\) Begins the production of a new glycogen molecule with the reactions of glycogenin b\) Involves the action of glycogen debranching enzyme c\) Involves transfer of glucose from CDP-glucose to a nonreducing end of a glycogen chain d\) Only occurs in the liver and muscle In muscle, what are two allosteric activators of glycogen phosphorylase? a\) Mg2+ and ATP b\) Ca2+ and AMP c\) Fructose-2,6-bisphosphate and citrate d\) AMP and glucose e\) cAMP and acetylCoA A G-protein coupled receptor binds its ligand, activating a heterotrimeric G-protein that stimulates a two-fold increase in cAMP. What important result on carbohydrate metabolism do the phosphorylases covalently activated by protein kinase A have? a\) They increase glycogen synthesis b\) They increase gluconeogenesis and decrease glycolysis c\) They inhibit hexokinase, especially in liver and muscle d\) They activate anaerobic metabolic pathways e\) They increase blood glucose concentration Regulation of phosphorylase a is by phosphorylation. However, this covalent modification increases or decreases activity without completely inhibiting it. The velocity plot is sigmoidal. What statement can be made about this enzyme? a\) It likely follows a Michaelis-Menten kinetic b\) Its reaction mechanism is likely exergonic c\) Its reaction mechanism includes covalent catalysis d\) The active site probably contains an SH2 domain e\) It is probably an allosteric enzyme Glycogen synthase kinase 3 (GSK3): a\) Functions only in regulation of glycogen synthase b\) Phosphorylates glycogen synthase only after glycogen synthase has been phosphorylated by another kinase c\) Is directly stimulated by insulin d\) Phosphorylates casein kinase II Which enzyme involved in glycogenesis and glycogenolysis is allosterically regulated? a\) Glycogen phosphorylase b\) Glycogen synthase c\) Phosphoprotein phosphatase 1 (PP1) d\) All of the answers are correct Which point is NOT a major difference between muscle and liver in terms of glucose regulation? a\) Muscles uses stored glycogen only for its own needs b\) During exercise, muscle undergoes very large changes in need of ATP c\) Muscle lacks the enzyme machinery for gluconeogenesis d\) Muscle cells lack a receptor for glucagon e\) None of the answers is correct Why are muscle and liver glycogen phosphorylase regulated differently? a\) Muscle only consumes glucose, and liver both consumes and secretes glucose b\) They are isozymes and are encoded by different genes c\) Muscle and liver have different glucose transporters d\) Muscle has no glycogen phosphorylase a isoform e\) Liver has no glycogen phosphorylase kinase Strenuous physical activity in vertebrates can cause an increase in AMP levels. What is the biochemical response in carbohydrate metabolism? a\) An increase in glycogen synthesis b\) Inhibition of glycolysis and stimulation of gluconeogenesis c\) An increase in fatty acid and carbohydrate catabolic pathways d\) Inhibition of transphosphorylation enzymes  substrate B in the diagram above activates this metabolic pathway, what else is substrate B involved in? A\) Activation of glycogen synthase B\) Activation of hormone sensitive lipases C\) The formation of Glycerol D\) Inhibition of gluconeogenesis The breakdown of glycogen into glucose A\) Differ in the liver and muscles in the quantity of glucose produced B\) Differe in the liver and muscles by the enzyme that converts glycogen to glucose-1-phosphate C\) Differ in the liver in muscles in the primer used to initiate the phosphate addition D\) Do not differ in the liver and muscles Which enzyme of the citric acid cycle would be most affected by an increase in Malonate in the inner mitochondrial matrix? A\) Aconitase B\) Malate Dehydrogenase C\) Succinate dehydrogenase D\) Fumarase E\) Succinyl- CoA synthetase Which of the following statements about the pyruvate dehydrogenase complex is false? A\) A-ketoglutarate is likely an evolutionary paralog due to the similarity in the E3 complex B\) The E3 complex dihydrolipoyl dehydrogenase enzyme functions with the use of NAD coenzyme bound allosterically C\) The PDH complex performs an irreversible oxidative decarboxylation reaction D\) The substrate channeling helps protect products from being used by other pathways In the breakdown of Palmitoleic Acid, a 16 carbons fatty acid, which of the following is true at the end of the citric acid cycle pathway? A\) After 16 cycles of fatty acid oxidation, 16 acetyl CoA yield 48 NADH, 16 FADH, and 16 ATP as the metabolic result B\) After 8 cycles of fatty acid oxidation, 8 acetyl CoA yield 24 NADH, 16 FADH, and 7 ATP as the metabolic result C\) After 7 cycles of fatty acid oxidation, 8 acetyl CoA yield 31 NADH, 15 FADH, and 7 ATP as the metabolic results D\) After 7 cycles of fatty acid oxidation, 8 acetyl CoA yield 24 NADH, 8 FADH, and 8 ATP are the metabolic results If someone had a perilipin deficiency what would likely be the result? A)fatty acid oxidation would occur but their storage could not be controlled B)fatty acid oxidation would occur but be unable to enter the bloodstream C)fatty acid oxidation would not occur because apolipoprotein B-48 would not be synthesized D\) fatty acid oxidation would not occur because apolipoproteins C-II would not be synthesized What is not a product of amino acid oxidation in humans? A\) Urea B\) Glucose C\) Ammonia D\) Glutamate What is the correct order of electron transfer of the following in the oxidative phosphorylation pathway 1)NADH 2)Cytochrome c 3)Cytochrome b 4)Ubiquinone 5)O2 6)Cytochrome a A\) 1,3,2,4,6,5 B\) 1,2,3,4,5,6 C\) 1,2,4,3,6,5 D\) 1,4,3,2,6,5 Which of the following would affect Complex 1 the most A\) Heme b misfolding B\) Hema a misfolding C\) Ingestion of Rotenone D\) Lack of copper in the diet Which of these hormones directly reduces hunger? A\) Adiponectin B\) Ghrelin C\) Leptin D\) Glucagon How does the Pasteur effect illustrate the dynamic nature of glucose metabolism? A\) by showing how glucose is metabolized exclusively in aerobic conditions B\) by demonstrating the rapid increase in glucose consumption under anaerobic conditions C\) by proving that ATP levels remain constant regardless of oxygen availability D\) by explaining how glucose 6-phosphate can be completely conserved during metabolic shifts Which enzyme is responsible for balancing glycolysis and gluconeogenesis through the regulation of fructose 2,6-bisphosphate (F26BP)? A\) pyruvate kinase B\) phosphofructokinase-1 (PFK-1) C\) fructose 1,6-bisphosphatase D\) ChREBP Which enzyme is responsible for decarboxylation in the Pyruvate Dehydrogenase Complex (PDH Complex)? A\) pyruvate Dehydrogenase B\) Dihydrolipoyl Transacetylase C\) Dihydrolipoyl Dehydrogenase D\) lipoate Which coenzyme is NOT associated with the Pyruvate Dehydrogenase Complex? A\) Thiamine pyrophosphate (TPP) B\) Flavin adenine dinucleotide (FAD) C\) Coenzyme Q D\) Nicotinamide adenine dinucleotide (NAD) During fatty acid oxidation, what is produced at the end of each B-oxidation cycle? A\) NADH, FADH2, ATP B\) Acetyl -- CoA and glycerol C\) Propionyl CoA and fatty acids D\) Carnitine and coenzyme A What is the primary function of B-oxidation in fatty acid metabolism? A\) Conversion of fatty acids into glucose B\) breakdown of fatty acids into acetyl -CoA C\) synthesis of triacylglycerols D\) transport fatty acids in the blood Which of the following organisms relies minimally on amino acid oxidation for energy? A\) Herbicores B\) Amphibians C\) Microorganisms D\) Carnivores What is the role of the Q cycle in complex III of the elctron transport chain? A\) transfer of electrons from succinate to ubiquinone B\) pumping protons from the matrix to the intermembrane space while transferring electrons to cytochrome C C\) reducing oxygen to water D\) catalyzing ATP synthesis using a proton gradient Which complex in the respiratory chain is inhibited by cyanide and carbone minoxide? A\) Complex 1 B\) Complex II C\) Complex III D\) Complex IV Which of the following hormones acts as a paracrine signal and is produced on demand? A\) Steroid hormones B\) eicosanoid hormones C\) thyroid hormones D\) retinoid hormones Which of the following is false regarding the utilization of glycogen within the feeder pathway? A. Intracellular glycogen is broken down by glycogen phosphorylase to result in glucose 1-phosphate. B. No priming takes place in the utilization of glycogen in feeder pathways during the preparatory phase. C. Glucose 1-phosphate is converted to glucose 6-phosphate by phosphoglucomutase. This is a reversible reaction. D. The enzyme catalyzes attack by inorganic phosphate (pink) on the terminal glucosyl residue (blue) at the nonreducing end of a glycogen molecule, releasing glucose 1-phosphate and generating a glycogen molecule shortened by one glucose residue. This is a hydrolysis reaction. What results under glucose-deprived adipocytes? I. Adipocytes begin to break down triacylglycerols stored in fat droplets. II\. ATP production via fatty acid oxidation occurs. III\. If glucose is not provided within a limited time period, cells that do not store fatty acids or perform fatty acid oxidation will begin to die off. IV\. Acetoacetate and ß-hydroxybutyrate result which cause the blood pH to increase. A. I, II, and III. B. I and II only. C. I, II, and IV only. Which of the following is true? A. Fructose-2,6-bisphosphate represents a low energy status of the liver cell which results in the increased activation of glycolysis. B. Upregulation of PKA eventually leads to the downregulation of glycogen synthase 3 (GSK3) in skeletal and heart cells. C. Downregulation of PKA in the liver results in the upregulation of PFK2 and downregulation of Fructose-2,6-bisphosphate. What happens to the activity of insulin when blood glucose levels are high? A. There is an upregulation of insulin. B. There is a downregulation of PKB. C. There is the downregulation of insulin-sensitive protein kinase D. There is the upregulation of glycogen phosphorylase. Which of the following is not a possible anaplerotic reaction? A. Pyruvate carboxylase will convert pyruvate to oxaloacetate. B. PEP carboxykinase will convert PEP into oxaloacetate. C. PEP carboxykinase will convert pyruvate to citrate. D. PEP carboxykinase will add bicarbonate onto PEP forming oxaloacetate. E. Malic will convert pyruvate to malate. Which of the following statements is false? A. PDH is allosterically activated by NAD+ and CoA. B. NADH and acetyl CoA represent a high energy status of the cell. C. PDH kinase phosphorylates PDH deactivating it. D. Phosphorylation of PDH kinase is a post-translational modification which regulates its activity. Which of the following enzymes is not a part of the ß-oxidation pathway? A. Thiolase B. enoyl-CoA hydratase C. Hexokinase D. acyl-CoA dehydrogenase Which of the following is not a part of the conversion of ketone bodies to acetyl-CoA? A. Thiolase B. ß-hydroxybutyrate dehydrogenase C. 3-ketoacyl-CoA transferase D. acyl-CoA dehydrogenase What will happen if we add an antifungal compound (ex: Venturicidin) or an antibiotic (ex: oligomycin) to a mitochondria suspended in a buffer solution containing an oxidizable substrate (ex: succinate), ADP, and Pi? A. ATP synthesis as well as the process of respiration will be halted as either compound will bind onto complex I preventing the oxidizable substrate from transferring its electron. B. The F0F1 ATP-synthase will be inhibited because either one will bind to the proton channel of the F0 subunit of the synthase preventing the consumption of oxygen and synthesis of ATP. C. The F0F1 ATP-synthase will be inhibited because either one will enter and become irreversibly binding in the F1 subunit of the synthase preventing the consumption of oxygen and synthesis of ATP. D. ATP synthesis will occur but at a lower rate as either compound functions to decrease in activity of F0F1 ATP synthase. Will ATP synthesis occur if an electrochemical gradient is artificially imposed across the inner mitochondrial membrane without the presence of an oxidizable substrate which acts as an electron donor? A. ATP synthesis can occur without the utilization of oxidative substrates for as long as an electrochemical gradient is artificially created and ADP as well as inorganic phosphates are provided. B. ATP synthesis will not occur as the electron of the oxidative substrate is required in order for electron flow to occur which in the process results in the pumping out of protons into the intermembrane space creating a proton gradient by which ATP synthesis is driven C. ATP synthesis can occur without the utilization of oxidative substrates for as long as an electrochemical gradient is artificially created. D. ATP synthesis will occur for as long as a reducing equivalent other than NADH is provided. What is true regarding the structure of α-granules with respect to β- granules? A. α-granules are rich in oligosaccharides, composed of 20-40 clustered β-granules B. α-granules are protein rich, and smaller than β -granules C. α-granules are larger than β-granules, rich in Cu ions D. α-granules are protein rich, and larger than β -granules The following is true regarding glycogenolysis except a\. Stimulated by epinephrine and glucagon b\. Stimulated by elevated cAMP which activates protein kinase A c\. Stimulated by insulin and epinephrine d\. Phosphorylase b is the less active form that reduces glycogen degradation. Where is the Pyruvate Dehydrogenase Complex Located? A. Mitochondrial Outer Membrane B. Mitochondrial Intermembrane Space C. Mitochondrial Cristae D. Mitochondrial Matrix Which two chemical mechanisms change pyruvate to acetyl-CoA in the pyruvate dehydrogenase complex? A. Oxidation & Aldol Condensation B. Dehydrogenation & Coa-Synthase reactions C. Decarboxylation & Dehydrogenation D. Oxidation & Reduction Which enzyme is not involved in Fatty Acid breakdown? A. Acyl-CoA dehydrogenase B. Enoyl-CoA dehydrogenase C. β-hydroxyacyl-CoA dehydrogenase D. acyl-CoA acetyltransferase Which statement is most accurate regarding B-Oxidation? A. Each FADH2 formed in β-oxidation donates electrons to complex I of the electron transport chain B. Monounsaturated fatty acids require two additional enzymes to enter the β-oxidation pathway. C. Peroxisomes carry out β-oxidation in animals D. Ketones are the bodies primary energy substrate. Which amino acid plays a key role in transport and distribution of amino groups into citric acid cycle? A. Lysine B. Alanine C. Arginine D. Glycine E. Margarine Which is the correct sequence of electron carrier in the electron transport chain? A. NADH \-\--\> Q \-\--\> cytochrome b \-\--\> cytochrome c1 \-\--\> cytochrome c \-\--\> cytochrome a3 \-\--\> cytochrome a \-\--\>O2 B. NADH \-\--\> Q \-\--\> cytochrome c1 \-\--\> cytochrome b \-\--\> cytochrome c \-\--\> cytochrome a \-\--\> cytochrome a3 \-\--\>O2 C. NADH \-\--\> Q \-\--\> cytochrome b \-\--\> cytochrome c1 \-\--\> cytochrome c \-\--\> cytochrome a \-\--\> cytochrome a3 \-\--\>O2 D. NADH \-\--\> Q \-\--\> O2 \-\--\> cytochrome c1 \-\--\> cytochrome c \-\--\> cytochrome a \-\--\> cytochrome a3 \-\--\> cytochrome b Which Enzyme Catalyzes Complex II? A. FADH Dehydrogenase B. Malate Dehydrogenase C. Succinate Dehydrogenase D. NADH dehydrogenase Which hormone is produced in the gastrointestinal tract when the stomach is empty, to stimulate feeding? A. Incretin B. Irisin C. Ghrelin D. Adipokines What has the immediate effect of increasing the rate of glycogen synthesis? a\) Increased AMP/ATP ratio b\) Increased secretion of insulin c\) Increased concentration of cAMP d\) Increased secretion of glucagon Which mechanism for enzyme regulation works the fastest? a\) Allosteric regulation b\) Synthesis of enzymes c\) Degradation of enzymes d\) Hormonal changes Why does the citric acid cycle only take place if there is oxygen present, even though oxygen does not participate directly? a\) It is needed to produce water b\) It removes toxic by products from the citric acid cycle c\) It accepts electrons from the electron transfer chain, reoxidizing NADH to NAD+ d\) It is needed to activate several enzymatic oxygenations in the cycle Which of these would not happen in a cell without phosphatase of the pyruvate dehydrogenase complex? a\) Increased lactate concentration b\) Increased citrate concentration c\) Decreased NADH and ATP concentrations Which of the following is true for b oxidation of fatty acids? a\) It is the same for saturated and unsaturated fatty acids b\) It happens in the intermembrane space of mitochondria c\) Lipoprotein lipase catalyzes the first step d\) Fatty acids are oxidized at C-3 to remove a two carbon unit Which is not true of fatty acid transport into the mitochondrial matrix? a\) It is the rate limiting step b\) Regulated by malonyl-CoA c\) Regulated by glucose levels d\) Once the fatty acyl groups enter the matrix they are committed to oxidation to acetyl-CoA Which compounds can serve as a direct acceptor of an additional amino group derived from amino acid catabolism? a\) fumarate b\) Asparagine c\) Glutamine d\) Succinate What is the consequence of an uncoupler, like 2,4-dinitrophenol (DNP), on oxidative phosphorylation? a\) It increases ATP synthesis by enhancing proton gradient formation. b\) It allows electron transport without ATP synthesis c\) It blocks electron flow at Complex I d\) It inhibits ATP synthase directly Which is statement is not true about electron transfer chain and oxidative phosphorylation? a\) NADH dehydrogenase complex, cytochrome C, and cytochrome oxidase are transmembrane proteins b\) Synthesized ATP must be transported into the intermembrane space before it can enter the cytosol c\) Cytochrome c and the F1 subunit of ATPase are peripheral membrane proteins d\) Ubiquinone and the F0 subunit of ATP synthase are peripheral membrane proteins When a person has diabetes, they can experience hyperglycemia. This is an excess of glucose in their blood. Normally the glucose would get reabsorbed by transporters in the kidney. In diabetics, not all blood glucose is reabsorbed and excreted in the urine. What is the explanation for this? a\) The binding affinity of these transporters is increased in diabetics b\) The Vmax of the transporter is reached at lower blood glucose levels c\) The binding capacity of the transporters has been exceeded d\) The transporters are inhibited by the presence of high levels of glucose Glycogen synthase activity is increased by which of the following? ○ A) Epinephrine ○ B) Glucose-6-phosphate ○ C) Insulin ○ D) Both B and C The regulatory enzyme that adds phosphate groups to glycogen phosphorylase and glycogen synthase is: ○ A) Protein phosphatase 1 ○ B) Protein kinase A ○ C) Glycogen synthase kinase ○ D) Both B and C What is the only membrane-bound enzyme in the citric acid cycle? ○ A) Succinate dehydrogenase ○ B) Citrate synthase ○ C) Isocitrate dehydrogenase ○ D) Fumarase Which product of the citric acid cycle is a precursor for amino acid synthesis? ○ A) Citrate ○ B) α-ketoglutarate ○ C) Succinate ○ D) Oxaloacetate What is the end product of β-oxidation for an even-numbered saturated fatty acid? ○ A) Acetyl-CoA ○ B) Propionyl-CoA ○ C) Malonyl-CoA ○ D) Pyruvate What is the fate of the electrons removed during the β-oxidation of fatty acids? ○ A) They are transferred to oxygen directly. ○ B) They are used to reduce FAD and NAD+. ○ C) They enter the glycolysis pathway. ○ D) They contribute directly to ATP synthesis. ATP synthase in the mitochondrial membrane synthesizes ATP using an energy source from: ○ A) A gradient of sodium ions ○ B) A gradient of potassium ions ○ C) A gradient of protons ○ D) Direct oxidation of glucose The primary role of coenzyme Q in the electron transport chain is to: ○ A) Transfer electrons between complex I and complex III ○ B) Act as a proton pump ○ C) Directly phosphorylate ADP ○ D) Oxidize glucose In the urea cycle, ornithine is converted into citrulline in which subcellular location? ○ A) Cytosol ○ B) Mitochondria ○ C) Endoplasmic reticulum ○ D) Golgi apparatus During fasting, which hormone increases gluconeogenesis in the liver? ○ A) Insulin ○ B) Epinephrine ○ C) Glucagon ○ D) Growth hormone In the beta oxidation of unsaturated fatty acids a\. cis-Δ3-dodecenoyl-CoA serves as a substrate for enoyl-CoA hydratase because this enzyme only works on cis double bonds. b\. cis-Δ3-dodecenoyl-CoA cannot serve as a substrate for enoyl-CoA hydratase because this enzyme only works on trans double bonds. c\. Δ3, Δ2-enoyl-CoA dehydrogenase is used to isomerize the trans-Δ3-enoyl-CoA to the cis-Δ2-enoyl-CoA, d\. Does not require auxiliary enzymes such as reductase and a isomerase Vitamin B12 serves as a coenzyme in which of the following pathways involving methyl-malonyl-CoA? a\. Conversion of propionyl-CoA to methyl-malonyl-CoA b\. Conversion of methyl-malonyl-CoA to succinyl-CoA c\. Decarboxylation of propionyl-CoA d\. Epimerization of methyl-malonyl-CoA Which of the following statements about Glucose-6-Phosphatase is correct? a\. It is found in all tissues, including muscle and brain. b\. It catalyzes the conversion of glucose-6-phosphate to glucose and inorganic phosphate in the liver. c\. It is directly involved in glycolysis to produce ATP. d\. It catalyzes the conversion of glucose-6-phosphate to glucose and inorganic phosphate in muscles. Aminotransferases can be associated with the coenzyme a\. Vitamin B6 b\. Vitamin B12 c\. Vitamin C d\. Vitamin A Killian is about to take a ride on the scariest roller coaster in the amusement park called the Krebs coaster. His epinephrine levels are rapidly increasing. He will most likely experience a a\. Upregulation of PKA which would stimulate glycogenolysis b\. Activate glycogen synthase, producing more glucose c\. A decrease in cAMP levels d\. Activation of glycogen phosphorylase a which promotes glycogenesis Oxidative damage to the cell is reduced by a\. Increasing electron leakage by ubiquinone b\. By using enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase c\. Neutralizing free radicals through antioxidants like vitamin C and vitamin E d\. Enhancing the production of reactive oxygen species (ROS) The malate-aspartate shuttle primarily functions to: a\. Transport ATP from the cytosol to the mitochondria. b\. Transfer electrons from cytosolic NADH into the mitochondrial matrix for oxidative phosphorylation. c\. Directly convert pyruvate to oxaloacetate in the cytosol. d\. Facilitate the transport of acetyl-CoA into the mitochondrial matrix for the TCA cycle Which of the following is true about Succinyl CoA a\. It inhibits citrate synthase. b\. It is a substrate for the enzyme succinate dehydrogenase in the TCA cycle. c\. It is involved in heme biosynthesis as a precursor. d\. It directly donates electrons to the electron transport chain Which of the following is false about succinate dehydrognase a\. Malonate is a competitive inhibitor b\. It is embedded in the adipocyte membrane c\. It donates electrons to the electron transport chain by converting FAD+ to FADH2 d\. This enzyme is embedded in the cristae Which of the following is a primary function of leptin? a\. Stimulate appetite and increase food intake b\. Regulate fat storage and signal satiety to the brain c\. Increase insulin secretion from the pancreas d\. Promote the breakdown of glucose in the liver Which steps of the citric acid cycle produce NADH? a\. Citrate → Isocitrate and Malate → Oxaloacetate b\. Isocitrate → α-Ketoglutarate and Malate → Oxaloacetate c\. Succinyl-CoA → Succinate and Isocitrate → α-Ketoglutarate d\. Citrate → Isocitrate and Succinyl-CoA → Succinate In amino acid catabolism, the first reaction for many amino acids is a(n): a\. decarboxylation requiring thiamine pyrophosphate. b\. hydroxylation requiring NADPH and O2. c\. oxidative deamination requiring NAD+. d\. reduction requiring pyridoxal phosphate. e\. transamination requiring pyridoxal phosphate. What is the function of Complex II in the electron transport chain? a\. It pumps protons across the mitochondrial membrane. b\. It oxidizes NADH to NAD+. c\. It reduces oxygen to water. d\. It transfers electrons from FADH2 to Coenzyme Q without pumping protons. Which of the following enzymes is used in gluconeogenesis but not in glycolysis, and what is its function? a\. Phosphoglycerate kinase, which converts 1,3-bisphosphoglycerate to 3-phosphoglycerate b\. Pyruvate kinase, which converts phosphoenolpyruvate (PEP) to pyruvate c\. Fructose-1,6-bisphosphatase, which converts fructose-1,6-bisphosphate to fructose-6-phosphate d\. Phosphofructokinase-1 (PFK-1), which converts fructose-6-phosphate to fructose-1,6-bisphosphate Which of the following best describes the role of Coenzyme Q (ubiquinone) in the electron transport chain? a\. It pumps protons across the inner mitochondrial membrane. b\. It transfers electrons directly from NADH to Complex III. c\. It shuttles electrons from both Complex I and Complex II to Complex III, while becoming reduced and oxidized in the process. d\. It accepts electrons from cytochrome c and donates them to oxygen. What molecule enters the citric acid cycle by combining with oxaloacetate? a\. Citrate b\. Acetyl-CoA c\. Pyruvate d\. FADH2 What is the role of increased \[cAMP\] in the regulation of glycogen metabolism? a\. It directly activates glycogen phosphorylase to break down glycogen into glucose-1-phosphate. b\. It activates PKA, which phosphorylates and activates phosphorylase b kinase, ultimately promoting glycogen breakdown. c\. It inhibits phosphorylase b kinase, preventing glycogen breakdown. d\. It activates PKA, which directly dephosphorylates glycogen synthase, promoting glycogen synthesis. Why is the carnitine shuttle important in fatty acid metabolism? a\. It directly generates ATP from fatty acids. b\. It transports fatty acids into the mitochondrial matrix for beta-oxidation. c\. It converts acetyl-CoA into citrate for the citric acid cycle. d\. It activates fatty acids for glycolysis. What is the primary location in the cell where fatty acid β-oxidation occurs? a\. Cytoplasm b\. Mitochondrial matrix c\. Golgi apparatus d\. Nucleus What is the role of phosphoprotein phosphatase 1 (PP1) in the regulation of glycogen metabolism? a\. PP1 removes phosphate groups from glycogen phosphorylase a, converting it into the less active form, phosphorylase b, and thus inhibits glycogen breakdown. b\. PP1 adds phosphate groups to glycogen phosphorylase b, converting it into the active form, phosphorylase a, and thus promotes glycogen breakdown. c\. PP1 activates phosphorylase b kinase, enhancing glycogen breakdown. d\. PP1 removes phosphate groups from glycogen synthase, converting it into its inactive form, and thus inhibits glycogen synthesis. Which of the following correctly describes the roles of ghrelin and incretins in regulating energy balance and glucose homeostasis? a\. Ghrelin is produced in the hypothalamus and stimulates insulin secretion, while incretins are produced in the stomach and stimulate feeding. b\. Ghrelin is produced in the gastrointestinal tract during fasting and stimulates feeding via the hypothalamus, while incretins are produced in the gut after a meal and enhance insulin secretion from the pancreas. c\. Ghrelin is produced in the pancreas and decreases glucagon secretion, while incretins are produced in the hypothalamus and stimulate feeding. d\. Ghrelin is produced in the gut during a meal and inhibits feeding, while incretins are produced in the pancreas and inhibit insulin secretion. What is the primary enzyme responsible for the breakdown of glycogen in muscle cells? A\) Hexokinase B\) Glucokinase C\) Glycogen phosphorylase D\) Amylase Which of the following is not a regulator of glycogen phosphorylase in liver cells? A\) Glucose B\) Insulin C\) Epinephrine D\) Glucagon What molecule acetyl-CoA combines with to start the citric acid cycle? A\) Oxaloacetate B\) Citrate C\) α-ketoglutarate D\) Succinate Which enzyme in the citric acid cycle is directly involved in substrate-level phosphorylation? A\) Citrate synthase B\) Succinate dehydrogenase C\) Succinyl-CoA synthetase D\) Malate dehydrogenase During β-oxidation, the acyl-CoA molecule is shortened by how many carbon atoms in each cycle? A\) Two B\) Four C\) One D\) Three Which coenzyme is necessary for the dehydrogenation steps in β-oxidation? A\) NAD+ B\) FAD C\) CoA D\) Both A and B Which complex in the electron transport chain does not pump protons? A\) Complex I B\) Complex II C\) Complex III D\) Complex IV The primary role of oxygen in cellular respiration is to: A\) Act as the final electron acceptor in the electron transport chain B\) Oxidize NADH back to NAD+ C\) Combine with carbon to form CO2 D\) Directly phosphorylate ADP What is the primary waste product formed in the liver during amino acid catabolism? A\) Ammonia B\) Urea C\) Creatinine D\) Uric acid Which hormone is crucial for the anabolic processes of storing glucose as glycogen? A\) Insulin B\) Glucagon C\) Epinephrine D\) Cortisol Which of the following statements about urea is not true? A\) Urea enters the bloodstream and is excreted into the urine. B\) Urea is produced in the liver as a byproduct of amino acid metabolism. C\) Urea is reabsorbed in large amounts by the kidneys for energy production. D\) Urea is a major nitrogenous waste product in humans. From which of following sources can cells not obtain fatty acid fuels from: A. B. C. D. Coenzyme A in the cytosol is used for A. B. C. D. Which of the following is not an electron- carrying molecule: A. B. C. D. Sugar nucleotides are suitable for biosynthetic reactions for each of the following except: A. B. C. D. Phosphoglucomutase does what? A. B. C. D. Lipoate is A. B. C. D. Adding a phosphate group to glucose in glycolysis does the following except: A. B. C. D. Insulin is an example of which type of hormone: a\. endocrine hormone that is released into the blood and carried to target cells throughout the body b\. paracrine hormone: released into the blood and carried to target cells throughout the body c\. autocrine hormone: affects the same cell that releases them d\. Paracrine: released into the extracellular space and diffuse to neighboring and target cells Xylulose 5-phosphate is an essential intermediate in the pentose phosphate pathway because it can be readily converted to a compound that feeds into glycolysis. Identify this compound: a\) Citrate b\) Fructose 1,6-bisphosphate c\) Glyceraldehyde 3-phosphate d\) 2-Phosphoglycerate If 4 mol of glucose are fully oxidized through the pentose phosphate pathway, the expected products are: A\) 2 mol of pentose, 4 mol of NADPH, and 8 mol of CO2. B\) 8 mol of pentose, 4 mol of NADPH, and 4 mol of CO2. C\) 4 mol of pentose, 8 mol of NADH, and 4 mol of CO2. D\) 4 mol of pentose, 8 mol of NADPH, and 4 mol of CO2. Which is a true statement regarding glycogen phosphorylase? a\) To activate this enzyme you MUST dephosphorylate it b\) It catalyzes the addition of glucose residues to the nonreducing end of a glycogen chain by the formation of (alpha 1 → 4) bonds. c\) catalyzes the breakdown of glycogen by hydrolysis of glycosidic bonds d\) cleaves glucose off glycogen by phosphorylating it to produce glucose 1-phosphate Which is not a direct cofactor in glycogen metabolism? a\) Ca2+ b\) Mg2+ c\) NADH d\) Vitamin B6 Which statement is true as to why oxaloacetate is kept at low concentrations? a\) The cell doesn't need a lot of it since it is constantly getting replenished b\) prevent inhibition of key enzymes in the citric acid cycle c\) Excess buildup leads to toxic byproducts d\) This leads to less wasteful ATP consumption Given that the reaction of malate to oxaloacetate has a ΔG°' of +29.7 kJ/mol, under which conditions can this reaction occur in the cell? a\) never occurs in the cell b\) occurs at a very very slow rate c\) can occur in the cell at certain concentrations of the substrate and product d\) can only occur in a cell if it is coupled to another reaction for which delta G is positive Which of the following statements concerning beta-oxidation of fatty acids is true? a\) Doesn't contribute to the electron transport chain, only ATP synthase b\) One FADH2 and two NADH are produced for each acetyl-CoA. c\) Contributes to ONLY complex 1 of the electron transport chain by producing FADH2 d\) The free fatty acid must be converted to a thioester before the process of beta-oxidation commences. The overall reaction for beta-oxidation of palmitoyl-CoA is: a\) palmitoyl-CoA + 7CoA + 7FAD + 7NAD+ + 7H2O⟶8 acetyl-CoA + 7FADH2+ 7NADH +7H+ b\) palmitoyl-CoA + 8CoA + 8FAD + 8NAD+ + 8H2O⟶8 acetyl-CoA + 8FADH2+ 8NADH +8H+ c\) palmitoyl-CoA + 8CoA + 8FAD + 8NAD+ + 8H2O⟶9 acetyl-CoA + 8FADH2+ 8NADH +8H+ d\) palmitoyl-CoA + 7CoA + 7FAD + 7NAD+ + 7H2O⟶7 acetyl-CoA + 7FADH2+ 7NADH +7H+ Which amino acid would be found in high concentrations after a long and intense workout? a\) histidine b\) Glutamine c\) alanine d\) Cystine e\) Calcium Which of the following electron carriers is sole/only an electron pair carrier? a\) FAD b\) Coenzyme Q c\) Cytochrome c d\) NADH Scientists have isolated a mobile electron carrier in the electron transport chain (ETC), which they call Carrier X. By reducing the ETC (through the omission of oxygen) and measuring the oxidation rates of Carrier X and known electron carriers, they establish the following sequence of electron transfer: NADH-\>Carrier X-\>Cyt b-\>Cyt c-\> Cyt a-\> O2 The carrier x is: a\) FADH2 b\) FAD c\) Coenzyme Q d\) Fe-S cluster Which of the following processes or enzymes is not positively regulated by insulin signaling? a\) GLUT 4 b\) PDH complex c\) Glycogen phosphorylase d\) Acetyl-coA carboxylase Which enzyme does not have a form of vitamin B as its coenzyme or prosthetic group? a\) most carboxylases b\) all aminotransferases c\) most dehydrogenases d\) most kinases Which of the following INCORRECTLY pairs a metabolic process with its site of occurrence? a\. Glycolysis -- Cytosol b\. Citric Acid Cycle -- Outer Mitochondrial Membrane c\. ATP Phosphorylation -- Cytosol and Mitochondria d\. Electron Transport Chain -- Inner Mitochondrial Membrane Which complex does NOT contribute to the proton-motive force? a\. Complex I b\. Complex II c\. Complex III d\. Complex IV Why is it preferable to cleave thioester links rather than typical ester links in aerobic metabolism? a\. Oxygen must be conserved for the electron transport chain. b\. Thioester hydrolysis has a higher energy yield. c\. Typical ester hydrolysis cannot occur in vivo. d\. Thioester cleavage requires more energy. Which of the following best characterizes the process of fatty acid synthesis? a\. Two reductions followed by dehydration and bond formation. b\. Reduction followed by activation, bond formation, dehydration, and reduction. c\. Activation followed by bond formation, reduction, dehydration, and reduction. d\. Activation followed by bond formation, oxidation, dehydration, and reduction The majority of triacylglycerols stored in adipocytes originate from: a\. Synthesis in the adipocyte. b\. Dietary Intake. c\. Ketone bodies. d\. Synthesis in the liver Which of the following amino acids will provide the most energy when degraded? a\. Glycine b\. Alanine c\. Valine d\. Isoleucine This reduction half-reaction is the last step of the electron transport chain: a\. O2 + 4e- + 4H+ → 2 H2O b\. NADPH → NADP+ + e- + H+ c\. NADP+ + e- + H+ → NADPH d\. Ubiquinone (Q) → Ubiquinol (QH2) Which process is expected to begin earliest in a prolonged fast? a\. Ketone bodies are used by the brain. b\. Glycogen storage is halted. c\. Proteins are broken down. d\. Enzyme phosphorylation and dephosphorylation. With prolonged fasting, the brain can turn to which alternative fuel for energy? a\. Fructose b\. Lactate c\. Ketone bodies d\. Fatty Acids How do hormonal controls of glycogen metabolism differ from allosteric controls? a\. Hormonal control is systemic and covalent. b\. Hormonal control is local and covalent. c\. Hormonal control is systemic and noncovalent. d\. Hormonal control is local and noncovalent. Which of the following tissues is most dependent on insulin? a\. Active skeletal muscle b\. Resting skeletal muscle c\. Cardiac muscle d\. Smooth muscle GLUT-2's affinity for glucose a\. is low; it allows glucose into the liver to initiate glycogenesis when blood-glucose concentrations are high. b\. is high; it should readily let out glucose into the bloodstream after G6P's cleavage to ensure proper blood-glucose levels. c\. varies; it could let in glucose into the liver or reject glucose completely depending on the current state of the receptor. d\. is moderate; it only allows glucose to enter the liver to balance glycogenolysis and glycogenesis when blood-glucose levels fall within a specific narrow range, ensuring proper levels. A β-granule of glycogen is labeled with 14C, inserted into a mammalian muscle cell, and then followed. After 6 hours of fasting, the glycogen is broken down by the muscle. In theory, during this process the label will be detectable a\. first in the cytoplasm, then in the mitochondria. b\. first in the cytoplasm, then in the bloodstream. c\. first in the mitochondria, then in the bloodstream. d\. in the mitochondria only. Which of the following molecules is not directly involved in anaplerotic reactions (ones that replenish TCA intermediates)? a\. Pyruvate b\. Oxaloacetate c\. Malate d\. Succinate Which of the following terms is not involved with the pyruvate dehydrogenase complex (PDH)? a\. Disulfide bonds b\. Carboxylation c\. FADH2 d\. Lysine A child began experiencing seizures, developed an enlarged liver, and was found to have high levels of octanoic acid in his blood. What could be a likely problem? a\. He has an MCAD deficiency, and has been fasting for some time, significantly lowering his glucose intake. b\. His glycogen stores are exceeding normal levels in the liver because of lack of glucose 6-phosphatase enzymes. c\. He has a deficiency in carnitine acyltransferase-1, and thus has a hard time transporting fatty acyl-CoA molecules into mitochondria. d\. He likely ate too much fat for his liver to process, which is causing the enlargement in the first place. At certain points, beta-oxidation of an odd-numbered fatty acid involves each of the following molecules except a\. biotin b\. NADH c\. thiamine d\. bicarbonate ion A human with deficiencies in the enzyme triose phosphate isomerase would likely a\. have a harder time breaking down glucose. b\. obtain energy from glucose faster. c\. exhibit increased lipoprotein lipase activity to break down triacylglycerols to G3P to be shunted into the mitochondria for energy production. d\. obtain energy from glucose slower. Which of the following pathways eventually produces roughly 2.5 equivalents of ATP via oxidative phosphorylation? a\. Phosphorylation of a cytosolic glycerol molecule to G3P, which enters mitochondria using G3P shuttles. b\. Conversion of a glyceraldehyde 3-phosphate molecule to pyruvate via glycolysis. c\. Entry of a malate molecule into mitochondria via malate-aspartate shuttles. d\. Oxidation of a succinate molecule using succinate dehydrogenase. Which statement regarding the electron transport chain is false? a\. Complex IV is ultimately shut down by cyanide b\. Complex III accepts electrons from cytochrome C c\. It is inhibited by a high \[ATP\]/\[AMP\] ratio d\. It is retarded by low TCA cycle activity Which of the following enzymes is used in more than one metabolic pathway? a\. Hexokinase b\. Cytochrome oxidase c\. Phsophoglucomutase d\. Pyruvate dehydrogenase An increase in which compound leads to the dephosphosphorylation and activation of phosphofructokinase 2 A. B. C. D. Which of the following processes does the glycogen branching enzyme catalyze: easy: A. B. C. D. E. Which statement is not correct regarding the citric acid cycle: A. B. C. D. E. Which cofactor is not required for the conversion of alpha ketoglutarate to Succinyl Co-A: medium A. B. C. D. E. Which of the following are required to transport a fatty acid in the cytoplasm to the mitochondrial matrix A. B. C. D. E. Which of the following statements is True regarding the Beta-oxidation of a Saturated Fatty Acid: A. Two NADH molecules are produced for each acetyl coA B. The free fatty acids must be converted to a thioester for the B-oxidation process to occur C. Triacylglyerols are oxidized during Beta oxidation to form three fatty acids and a glycerol D. One enzyme required in the oxidation is 2,4-dienoyl reductase E. About 209 ATP are produced from the complete oxidation a 16 carbon fatty acid. Which situation requires the breakdown of amino acids via oxidative degradation A. B. C. D. E. Which of the following do NOT produce Ubiquinone (QH2) A. B. C. D. E. Which of the following is necessary to produce heat instead of ATP in brown fat? Medium A. B. C. D. E. Which of the following statements regarding skeletal muscle is true A. B. C. D. E. Which of the following is a cofactor for Isocitrate Dehydrogenase? A. Ca2+ B. NAD+ C. NADPH D. Mn2+ Geoffrey is an athlete training for the Olympics. A teammate recommended that he start taking NADH supplements. What effect would this have metabolically? A. Glycolysis would occur more rapidly, giving him more energy B. Glycolysis would not occur at all because NADH inhibits PFK-1 C. NADH is a cofactor for NADH which, when bound, increases Citrate production D. NADH inhibits that Krebs Cycle How do bears survive during hibernation, despite never drinking for 2-4 months straight? a\. They rely on metabolic water which is produced from fat reserved b\. Their metabolism is much slower and does not require water c\. Their bodies absorb moisture from the air d\. They do have to wake up periodically to drink water How many Acetyl CoAs would a 16 carbon molecule undergo? a\. 7 b\. 8 c\. 4 d\. 9 A scientist walked into his lab after the weekend and noticed that a bottle of Antimycin A was spilled onto a sample of tissue that he was studying. How would the cells in the sample be affected? a\. The cells' plasma membrane would become impermeable to ions b\. The Q cycle would not be able to occur c\. Complex I would be inhibited d\. Complex II would be inhibited e\. Beta oxidation would not occur Which of the following will have a positive impact on cellular respiration? a\. Retinone b\. Malonate c\. Antimycin A d\. PKA e\. NAD+ Which of the following helps increase body temperature? a\. Leptin b\. UCP1 c\. Ghrelin d\. Cortical e\. Calcitonin Which of the following plays a significant role in the health and function of Red Blood Cells? a\. Kupffer Cells b\. White blood cells c\. Myocytes d\. Selectins What type of bond does the debranching enzyme break during glycogen metabolism? a\. α-1,4-glycosidic bond b\. α-1,6-glycosidic bond c\. β-1,4-glycosidic bond d\. α-1,2-glycosidic bond Which of the following is controlled by hormones and inhibits the production of Glycogen a\. GSK3 b\. cAMP c\. Insulin d\. PKA Which of the following amino acids CANNOT be turned into Krebs cycle Intermediates? a\. Glutamate b\. Alanine c\. Aspartate d\. Glutamine e\. Leucine Which of the following molecules must phosphorylate glycogen synthase kinase 3(GSK3) in order for it to function? a\. Glycogen synthase a b\. Glycogen synthase b c\. Casein kinase II (CKII) d\. Glycogen synthase What is the function of phosphoprotein phosphatase 1 (PP1)? a\. Removes phosphoryl groups from phosphorylase a converting it to phosphorylase b b\. Removes phosphoryl groups from phosphorylase b converting it to phosphorylase a c\. Allows the release of ammonia regenerating ∝-ketoglutarate d\. Donates its amino group to ∝-ketoglutarate regenerating glutamate and pyruvate How many turns does the Krebs cycle make in order to generate a glucose molecule that enters cellular respiration? a\. 1 b\. 2 c\. 3 d\. 4 Which of the following activates the PDH cycle? 1\. NAD+ 2\. ATP 3\. NADH 4\. Acetyl-CoA X-linked adrenoleukodystrophy (XALD) is caused by a mutation in a gene that encodes: a\. CAT I b\. CAT II c\. Peroxisomal membrane transporter d\. Carnitine translocase What\'s the significance of acetoacetate conversion to ketone bodies? a\. To allow the fatty acid chain to cross the blood brain barrier in times of starvation to be used as a secondary energy source b\. To prevent ketone body accumulation in the liver, which could lead to liver toxicity. c\. To facilitate the storage of ketone bodies in adipose tissue for later use. d\. To directly activate gluconeogenesis in the liver for glucose production. Which of the following is an alternate name for Complex II? a\. Cyt-b-oxidoreductase b\. Cytochrome oxidase c\. Succinate dehydrogenase d\. NADH dehydrogenase What is the function of heme b in the electron transport chain a\. It serves as a molecule that has a strong absorption for visible light b\. It alternates between oxidized and reduced states, enabling the ETC c\. It serves as a pathway to shuffle electrons into the the ATP synthase d\. It reduces electron leakage minimizing the chances of ROS Pyridoxal phosphate (PLP) is also known as which vitamin? a\. Vitamin E b\. Vitamin B1 c\. Vitamin B5 d\. Vitamin B6 What type of hormone can bind to a nuclear receptor? a\. Norepinephrine b\. Steroid c\. Prostaglandins d\. Peptide