Science Homework Help

Please confirm for me if the following answers are correct. Thank you

1.Which of the

following tissues can use glucose, but not fatty Acids, as a source of fuel?A. Skeletal MuscleB. Cardiac tissueC. LiverD. Red Blood CellsE. Adipose: D. Red Blood Cells__________Brain and RBC

2.Within the red blood cell, NADPH is required for which of the following processes?A. The Conversion of pyruvate to Acetyl CoAB. The Oxidation of hemoglobinC. The conversion of pyruvate to lactateD.The synthesis of ribulose 5-PhosphateE. The Reduction of Glutathione:

Answer: E. The Reduction of Glutathione

3.There are several anaplerotic reactions required to replenish intermediates of the TCA cycle. All of the following compounds can be used for these anaplerotic reactions EXCEPT:A. AspartateB. PropionylC. GlutamateD.Odd Chain fatty acidsE. Glucose:

Answer: E. Glucose_________________________________CAN BE USED: Pyruvate, Aspartate, Glutamate, Beta Oxidation of fatty acids, adenylosuccinate; PEP carboxylase and malate dehydrogenase; Glutamine

4.Hereditary fructose intolerance is a rare recessive disease caused by a mutation in exon 5. The mutation creates a new Ahall restriction within the exon. In this graphic:——— ——— 306===== ——— ===== ——— 183===== ——— ===== ——— 123husband wife jack jilla) the husband had al b deficiencyb) the wife has 2 wild allellsc) Jill has wild recessived) jack and jill have same genes:

Answer: b) the wife has 2 wild allells

5.A 3-year-old boy who presented with generalized hypotonia, severe psychomotor development delay, and severe lactic acidosis following ingestion of a high carbohydrate meal was diagnosed with a deficiency in pyruvate dehydrogenase (X-linked recessive).Supplementation of which vitamin may be beneficial to this individual:A. Pyridoxal Phosphate (PLP)B. FolateC. Cobalmin (B12)D. Thiamine:

Answer: D. Thiamine

6.Which of the following hormones binds to a receptor tyrosine kinase?A. EpinephrineB. CortisolC. GlucagonD. Insulin:

Answer: D. Insulin———-Receptor tyrosine kinase are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Tyrosine kinase contain insulin growth factor which can bind to glucogan

7.Which of the following is true regarding single point mutations to a genomic DNA sequence?A . changes to the DNA sequence will always result in an amino acid change in the primary sequenceB. single nucleotide changes to the DNA sequence may have no impact on the primary sequence of a proteinC. single nucleotide changes to DNA will always introduce a frame shiftD. single nucleotide changes will always introduce a nonsense mutation:

Answer:B

8.NADH generated in the cytosol must be transported across the mitochondrial membrane in order to be oxidized by the electron transport chain. Which can be used to facilitate movement of cytosolic NADH into the mitochodria?a) Malate-aspartate shuttleb) GLUT 4 Transportc) Citrate chuttled) Na/K+ ATPase pump:

Answer: a) Malate-aspartate shuttle___________________NADH generated in the cytosol must be transported across the mitochondrial membrane in order to be oxidized by the electron transport chain,which can be used to facilitate movement of cytosolic NADH into the mitochodria.this meshanism is called shuttle mechanism.

9.Prokaryotic genes are organized which contain a series of genes that are regulated by a common promoter. In the case of an inducible operon, the operaon is transcribed:a) when the inducer is bound tt the repressorb) when the repressor is bound to the operatorc) when the inducer is bound ot the operatord) when both the repressor and inducer are bound to the operator:

Answer: A) when the inducer is bound tt the repressor

10.When the pancreatic beta cells sense an increase in glucose, the release of insulin is facilitated through which of the following mechanisms?a) increase in intracellular calciumb) incrase in intracellular potassiumc) decrease in intracellular ATPd) decrease in intracellular Calcium:

Answer: A) an increase in intracellular calcium.

11.You have identified a mutation in the c subunit in the ATP synthase. The mutation changes the glutamate residue, (that facilitates proton pumping into the mitochondrial matrix), to a glycine. The inability to dissipate the proton gradient will have which of the following impacts on the electron transport chain?A) Decreased ATP synthesisB) Increased ATP synthesisC) Increased NADH oxidationD) Increased Oxygen Consumption:

Answer:A

12.During an overnight fast, which of the following pathways is the primary source of glucose required for the maintenance of blood glucose levels?A) Lipolysis from adipose storesB) Muscle glycogenolysisC) Muscle Protein CatabolismD) Liver Glycogenolysis:

Answer:D) Liver Glycogenolysis______________________Liver glycogen is broken down for gluconeogenesis.

13.Glycogen synthesis and degradation in the liver and muscle is very similar. Which of the following enzymes is not used in both muscle and liver for those metabolic pathways?A) Glycogen PhosphorylaseB) HexokinaseC) Glycogen synthaseD) PhosphoglucomutaseE) UDP- Glucose pyrophosphorylase:

Answer:B) Hexokinase

14.Insulin is a peptide hormone secreted by the beta cells of the pancreas in response to elevated levels of blood glucose. Locally, insulin will inhibit the release of glucagon from alpha cells in the pancreas, and it will also impact the metabolism of many peripheral tissues. The actions of insulin are best described as which of the following?a) autocrineb) paracrine and autocrinec) endocrined) paracrine and endocrine:

Answer:(d) Paracrine and endocrine__________________Insulin acts as a messenger to instruct the body’s cells to absorb glucose, in effect reducing blood glucose levels.

15.Rotenone is an inhibitor of complex 1 in the electron transport chain. Which of the following will not occur as a result of the addition of rotenone?A) Decreased Oxidation of FADH2B) Decreased production of ATPC) Decreased oxygen consumptionD) Decreased oxidation of NADH:

Answer: A) Decreased Oxidation of FADH2___________The addition of rotenone to the ETC does what? – inhibits transfer of electrons from complex 1 to CoQ (prevents NADH from entering complex 1)-H+ movement ceases-ATP not synthesized

16.Based on the following schematic, which statement best describes the acid/base properties of guanine?Image Link – http://oi68.tinypic.com/ogwbp0.jpgA ) at physiological pH, guanine will be positively chargeB ) at physiological pH, guanine will be negatively chargeC) at physiological pH, guanine will be neutralD) at physiological pH, guanine will be an effective buffer against a baseE) at physiological pH, guanine will be an effective buffer against an acid:

Answer: C-at pH, guanine will be neutral

17.Following a meal, fructose 2, 6 bisphosphate levels will be elevated in the liver. Under these conditions which of the following will be dephosphorylated and inactive?a) pryuvate kinaseb) glycogen synthasec) PFK1d) glycogen phosphorylase:

Answer: b) glycogen synthase

18.Given the following enzyme pathway, A→B→C→DAnd given that the ΔG0′ for A→B is -8; for B→C is +6; and for C→D is +1Then the ΔG0′ for A→D is:A) +5B) +2C) 0D) -1E) -2: simple subtraction: -1

19.In the liver, the pyruvate dehydrogenase complex (PDC) would be dephosphorylated and active when which of the following compounds or hormones is elevated?A) ATPB) PyruvateC) AcetylCoAD) NADHE) glucagon:

Answer: E) glucagon

20.All of the following are part of the Cori Cycle EXCEPT:A) ATP is produced by the conversion of lactate to glucoseB) Lactate is the result of anaerobic glycolysis in a number of tissuesC) Lactate travels to the liverD) Lactate is converted to glucose in the liverE) Glucose travels from liver to other tissues:

Answer: A) ATP is produced by the conversion of lactate to glucose_____________FALSE:ATP is produced by the conversion of lactate to glucoseTRUE:Lactate is the result of anaerobic glycolysis in a number of tissuesLactate travels to the liverLactate is converted to glucose in the liverGlucose travels from liver to other tissues

21.Which of the following is a monosaccharide?A) MaltoseB) LactoseC) GalactoseD) Amylose:

Answer: C) Galactose

22.Which of the following compounds or hormones will not facilitate the process of skeletal muscle glycogenolysis?A) EpinephrineB) GlucagenC) Ca ++D) AMP:

Answer: C) Ca ++

23.The primary GLUT transporter used by the liver is ____________ and the primary GLUT transporter used by the skeletal muscle is _______________:A) GLUT4; GLUT2B) GLUT1;GLUT4C) GLUT2 ; GLUT4D) GLUT5; GLUT2:

Answer: C) GLUT2, GLUT4

24.Glucogan will influence the metabolism in the liver, adipose, and skeletal muscle during fasting. Which of the following is consistent with the impact of glucogon?A) Glucogan will increase output of glucose by liverB) triaglycerol synthesis in adiposeC) oxidation of glucose in muscleD) oxidation of glucose in live:

Answer: A) Glucogan will increase output of glucose by liver___________________Because glucogan control the mechanism of glycogenolysis and gluconeogenesis under the fasting condition glucogan provide the glucose by these two mechanism

25.Chronic smokers have an elevation of guanine residues associated with a benzopyrene ring. This bulky distortion to the DNA is repaired through which of the following mechanisms?A) Nucleotide excision repairB) Bases excision repairC) Mismatch repairD) Homologous end joining:

Answer: A) Nucleotide excision repair

26.Under conditions of anaerobic glycolysis pyruvate is primarily oxidized to which compound:a) malateb)lactatec) Acetoly CoAd) isocitrate:

Answer: B) Lactate

27.Insulin is a major metabolic hormone. Its Primary role on metabolism is best summarized by which of the following statements?A) It mobilizes glycogen stores during acute stressB) It activates processes to mobilize fuel storesC) It stimulates protein synthesis during fastingD) it promotes fuel storage and growth after a meal:

Answer: D) it promotes fuel storage and growth after a meal_____________Insulin secret from pancrease by Beta cells it function into control blood sugar level. so it can control it by mobilize fuel because our major fuel is sugar.

28.Certain conditions such as excessive alcohol consumption can increase the ratio of NADH/NAD+ in the mitochondria. This will directly inhibit which of the following enzymes?a) PFK1,b) PDC (kinase)c) isocitrated) succinate thiokinase:

Answer: B) PDC – Pyruvate Dehydrogenase Complex

29.The oxidation of glucose produces NADH. NADH can be oxidized in the mitochondria and in this process the terminal electron acceptor in the electron transport chain is which of the following compounds?a) NADHb) FADc) O2d) H2O:

Answer: c) O2

30.What is the oxidizing agent in the following reaction?^oh (Ethanol) + NAD+ <=> o=^h (Acetaldehye ) + NADH + H+A) EthanolB) NAD+C) AcetaldehyeD) NADH:

Answer: B) NAD+ is the oxidizing agent in this reaction because it is getting reduced by consuming one electron. Whichever product is reduced, i.e. gains an electron (- / H+) ]

31.Several TCA cycle intermediates can be used as a substrate for the synthesis of other compounds. Succinyl CoA is an intermediate that is directly used for the synthesis of which of the following compounds?a) R5Pb) G3PC) HemeD) purines:

Answer: C) Heme

32.A 2-year-old boy is recently diagnosed with red-green color blindness which is an X-linked recessive disorder. Which of the following represents the genotype of this individual?A) X’Y ( X’ recessive X allele and Y chromosome)B) Rr (one wildtype autosomal allele and one recessive allele)C) XY ( X – wild type X allele and Y chromosomeD) rr ( two recessive autosomal alleles):

Answer: A) X’Y ( X’ recessive X allele and Y chromosome)

33.Dinitrophenol is an uncoupler of the electron transport chain. The addition of dinitrophenol will have which of the following impacts to the cell?a) increase oxygen consumptionb) increase ATP productionc) decrease NADH oxidationd) increase protein concentration in the cytosol:

Answer: a) increase oxygen consumption

34.Under conditions when a cell only needs to use the nonoxidative portion of the pentose phosphate pathway to synthesize ribose 5-phosphate, the elevated levels of NADPH in the cell will inhibit which of the following enzymes?A) transaldeseB) alpha-ketoglutarate dehydrogenaseC) transketolaseD) G-6-phosphate dehydrogenaseE) Glucose 6- phosphatase:

Answer:D)G-6-phosphate dehydrogenaseRibose 5-P only needed, so only the nonoxidative reactions. High NADPH inhibits glucoe-6-phosphate dehydrogenase, so transketolase and transaldolase are used to convert fructose 6-P and glyceraldehyde 3-P to ribose 5-P.

35.Which of the following intermediates is a feed-forward activator of pyruvate kinase?A) Glucose-6-PhosphateB) Fructose-1-6-biphosphateC) Fructose 6 PhosphateD) Glyceraldehyde-3- phosphateE) Phosphoenolpyruvate:

Answer:B) Fructose-1-6-biphosphate

36.Which of the following activators is correctly paired with the glycolytic or TCA cycle enzyme that it activates?A) Glucose-6-Phosphate : HexokinaseB) ATP: alpha-ketoglutarate dehydrogenaseC) ATP: Pyruvate kinaseD) Fructose-2-6-biphosphate : phosphofructokinase 1 (PFK1)E) Citrate : citrate synthase:

Answer:D) Fructose-2-6-biphosphate : phosphofructokinase 1 (PFK1)

37.Skeletal muscle does not have the enzyme glucose 6-phosphatase, which is required to dephosphorylate glucose-6-P released during the process of glycogenolysis. As a result of this, glucose 6-P released from muscle glycogen stores is primarily used for which of the following processes?A ) it enters the glycolytic pathway and is oxidizedB) it helps maintain blood glucose levelsC ) it is used for protein synthesisD ) it is used as a substrate for glycogen synthesis:

Answer: A) it enters the glycolytic pathway and is oxidized

38.In the red blood cell, glucose can be oxidized to two primary products. One of the oxidation products is ribulose 5-phosphate, and the other is which of the following compounds?A) Acetyl CoAB) Carbon DioxideC) EthanolD) Lactate:

Answer:D) Lactate

39.Besides its role in glycogen synthesis, which of the following directly relies on UDP-glucose?A) galactose metabolismB) gluconeogenesisC) glycolysisD) sucrose metabolismE) fructose metabolism:

Answer:A) galactose metabolism

40.Hereditary fructose intolerance (HFI) is a rare recessive disorder that is caused by a mutation in the aldolase B gene. As a result of this disorder individuals may have all of the following symptoms EXCEPT:a) inability to metabolize lactoseb)reduced blood glucose levels during fastingc)reducing sugar in the urined)hepatomegaly:

Answer:a) inability to metabolize lactose___________- WILL NOT HAVE:-inability to metabolize lactoseWILL HAVE:-reduced blood glucose levels during fasting-reducing sugar in the urine-hepatomegaly

41.When glucagon binds its receptor there is an increase in the second messenger, cAMP. cAMP levels can be decreased by which of the following enzymes?A) Adenylyl cyclaseB) Protein Kinase AC) Phosphoinositide-dependent protein kinase (PDK 1)D) Phosphodiesterase:

Answer:D) Phosphodiesterase

42.Which of the following statements best describes the action of epinephrine?a) It promotes of fuel storage after a mealb) It promotes of protein synthesisc) facilitates maintenance of glucose during fastingd) it works to mobilized fuels during acute stress:

Answer:d) it works to mobilized fuels during acute stress________________increased release of glucose

43.An individual with a deficiency in Pyruvcute stressate Dehydrogenase Complex (PDC) will have elevated levels of which metabolite after consuming a meal high in carbohydrates?A) OxaloacetateB) LactateC) AcetylCoAD) Citrate:

Answer:B) Lactate

44.Phenylketonuria (PKU) is an autosomal recessive disorder that can be caused by a defect in phenylalanine hydroxylase. Phenylketonuria can also present due to a deficiency in which of the following vitamins or cofactors?A) Tetrahydrobiopterin (BH4)B) Cobalmin (B12)C) Pyridoxal Phosphate (B6)D) Tetrahydrofolate (TH4):

Answer:A ) cofactor: Tetrahydrobiopterin (THB, BH4)

45.Under conditions of strenuous exercise, gluconeogenesis occurs primarily in the _______ using _______ formed in the skeletal muscle.A) liver; lactateB) liver; propionateC) kidney; acetyl-CoAD) kidney ; alanineE) Muscle ; glycerol: A) liver; lactate

46.The movement of glucose from the intestinal lumen into the blood stream requires secondary active transport. Which type of work is required?a) Transport workb) passive workc) mechanical workd) biochemical work:

Answer: a) Transport work

47.A substitution mutation occurs in the GRE (glucocorticoid response element) making it unrecognizable to the glucocorticoid receptor. What impact would this have on the transcription of the gene downstream of this element?a) transcription unchanged but mutation incorporated into transcriptb) transcription unchanged but translation increasedc) increased translation of downstream gened) decreased translation of downstream gene: b) transcription unchanged but translation increased

48.NADPH is used by most cells for which of the following processes?A) To produce ribose-5-P from glyceraldehyde-3-P and fructose-6-PB) A reducing agent in detoxification reactionsC) An oxidizing agent in reductive biosynthesisD) A substrate for transketolase reactions:

Answer:B) A reducing agent in detoxification reactions

49.When Ca++ increases in muscle cells, muscle contracts and all of the following happen EXCEPT:A) The oxidation of NADH and FADH2 by the electron transport chain increasesB) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in NADHC) Isocitrate dehydrogenase is allosterically activated by increases in ADPD) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in Ca++E) The concentration of AMP and ADP increase and the concentration of ATP decreases:

Answer:B) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in NADH

50.The mechanism of action of the pyruvate dehydrogenase complex (PDC) relies on the use of three prosthetic groups in the enzyme active site. Which of the following lists these three groups in the order that they are utilized during the oxidation of pyruvate?A) NAD+ ; FAD ; LipoateB) FAD ; Thiamine pyrophosphate ; NAD+C) Thiamine pyrophosphate; Lipoate; FADD) FAD ; Thiamine pyrophosphate ;Lipoate:

Answer:C) Thiamine pyrophosphate; Lipoate; FAD______________________________Prosthetic groups:thiamine pyrophosphate (TPP), Lipoamide (and Coenzyme A),FAD/NAD+Enzymes:1. Pyruvate dehydrogenase2. Dihydrolipoyl transacetylase3. Dihydrolipoyl dehydrogenase1.E1: Pyruvate dehydrogenase which uses thiamine pyrophosphate (TPP) as its prosthetic group.2.E2: Dihydrolipoyl transacetylase which uses lipoamide and coenzyme A (also known as coASH) as its prosthetic groups.3.E3: Dihydrolipoyl dehydrogenase which uses flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NAD+) as its cofactors.