Biochimica secondo semestre

1. Which of the following pairs of hormones work to regulate the levels of calcium in the blood?. Calcitonin & PTH. TSH & FSH. Insulin & Glucagon. Thyroxine & TSH. T3 & T4.

2. Which combination of hormones helps a mother to produce milk and nurse her baby?. Prolactin & calcitonin. Oxytocin & prolactin. Follicle-stimulating hormone and luteinizing hormone. Luteinizing hormone and oxytocin. Oxytocin, prolactin, and luteinizing hormone.

3. The lipid-insoluble hormones: Cytoplasmic receptors are specific for these hormones. Can diffuse through plasma membrane. Hormone receptors are integral membrane proteins. Serum concentration is very high. receptors are located inside target cells.

4. Which of the following is secreted by the pancreas?. Cortisol. Glucagon. Thyroxine. Oxytocin. Growth hormone.

5. Which of the following hormones is produced as part of the stress response?. Cortisol. ADH. Insulin. Prolactin. Thyroxine.

6. Which of the following pairs of hormones work to regulate the glucose in the blood?. TSH & FSH. Insulin & glucagon. Calcitonin & PTH. Thyroxine & TSH. T3 & T4.

7. Iodine is necessary for the production of: Corticosteroids. glucagon. Glucagon hormone. Thyroid hormones: thyroxine & triiodothyronine. Growth hormone.

8. Antioxidant defense contains, except: ATP Synthase. Glutathione peroxidase. Vitamin C. Glutathione. Superoxide dismutase.

9. The synthesis of complex molecules by using simple precursors of smaller units is named as: Catabolism. Anabolism. Amphibolism. Amphobolic. Metabolism.

10. What molecule will form when hydrogen ions flow down the electrochemical gradient through ATP synthase complexes in mitochondria?. Water. ATP. ADP. carbon dioxide. oxygen.

11. The carriers for the electron transport system are located. Within the cytoplasm of a cell. On the cristae of mitochondria. Within the matrix of mitochondria. Within the Golgi apparatus. On the cell wall.

12. For every NADH2 that enters the electron transport system, ATP result: 1. 2. 3. 5. 10.

13. Salivary amylase is active in which of the following parts of the digestive system?. Stomach. Small intestine. Mouth. Liver. Pancreas.

14. Starch is a: a. Lipid. b. Amino acid. c. Disaccharide. d. Protein. e. Polysaccharide.

15. Enzyme involves in carbohydrates digestion is: a. Amylase. b. Pepsin. c. Gastric lipase. d. Transaminase. e. Urease.

16. Carbohydrates stores are mainly present in: a. Liver. b. Brain. c. Adipose tissue. d. Intestine. e. Kidney.

17. Which of the following statements is NOT correct about glycolysis?. a. Glycolysis takes place within the cytoplasm. b. Glycolysis uses two ATP but forms four ATP, resulting in a net gain of two ATP molecules. c. During glycolysis, two NADH are produced as substrate oxidation occurs. d. Glycolysis begins with glucose and ends with four pyruvate molecules. e. During glycolysis, two C3 are produced.

18. The end product of anaerobic glycolysis is. a. Water. b. Carbon dioxide. c. Lactate. d. Heat. e. Acetyl CoA.

19. In what form does the product of glycolysis enter the TCA cycle?. a. Acetyl CoA. b. Pyruvate. c. NADH. d. Glucose.

20. Lipid stores are mainly present in: a. Liver. b. Brain. c. Adipose tissue. d. Muscle. e. Kidney.

21. Enzyme involves in lipids digestion is: a. Amylase. b. Pepsin. c. Gastric lipase. d. Transaminase Urease.

22. Chylomicrons are synthesized in: a. Blood. b. Liver. c. Intestine. d. Brain. e. Pancreas.

23. During each cycle of fatty acids B-oxidation: a. One carbon atom is removed from the carboxyl end of fatty acid. b. One carbon atom is removed from the methyl end of fatty acid. c. Two carbon atoms are removed from the carboxyl end of fatty acid. d. Two carbon atoms are removed from the methyl end of fatty acid. e. Two carbon atoms are added to the carboxyl end of fatty acid.

31. The function of bile salts in the intestine is: a. Activator of lipase. b. Co-factor for cholesteryl-esterase. c. Emulsifier. d. Inhibitor of lipid absorption. e. Enzyme.

32. Fatty acids breakdown occurs in: a. endoplasmic reticulum. b. cytoplasm. c. cell membrane. d. mitochondrial matrix. e. microsomes.

33. The end product of fatty acid synthesis is: a. Linoleic acid. b. Arachidonic acid. c. Stearic acid. d. Palmitic acid. e. Butiric acid.

34. Hormone-sensitive lipase is regulated by the action of the hormones: a. Insulin and noradrenaline. b. Thyroxine and vasopressin. c. Glucagon and calcitonin. d. Steroidal hormones. e. Growth hormone.

35. Enzyme involves in proteins digestion is. a. Amylase. b. Pepsin. c. Gastric lipase. d. Transaminase. e. Urease.

36. The transfer of an amino group from one amino acid to an a-keto acid is called: a. Transamination. b. Deamination. c. Reamination. d. Examination. e. Phosphorylation.

37. Which of the following is the most likely source of ketone bodies?. a. Protein breakdown. b. Fatty acids breakdown. c. Glucose breakdown. d. Glycerol breakdown. e. Side chain of cholesterol.

38. Urea is synthetized in: a. Mitochondria. b. Cytoplasm. c. Lysosomes. d. Both cytoplasm and mitochondria. e. Plasma membrane.

39. Within the cytoplasm of hepatocytes, bilirubin is conjugated with: a. UDP-glucose. b. Albumin. c. Glucuronic acid. d. Ferritin. e. Plasma enzymes.

40. Urea is the end product of the. a. Krebs cycle. b. Gluconeogenesis. c. Glycolysis reactions. d. Protein Metabolism.

41. Which hormone stimulates protein synthesis and general growth in the body?. a. STH. b. Aldosterone. c. LH. d. epinephrine. e. Insulin.

42. Pyruvate is the end product of the _____reactions. a. Krebs cycle. b. Electron transport system. c. Glycolysis. d. Cori Cycle. e. carbohydrate digestion.

43. Choose the false answer. a. The digestion of carbohydrates predominantly occurs in the small intestine with pancreatic amylase. b. The dextrins are broken down by glucosidases in the small intestine. c. The mitochondria represent the site of glycolysis. d. All of the enzymes of glycolysis are found in the cytosol. e. The irreversible reactions of glycolysis are catalyzed by kinases.

44. Choose the correct answer. a. A high Energy Phosphate is transferred directly from a substrate to ADP thus forming ATP refers to oxidative phosphorylation. b. In Complex II a molecule of ATP is formed. c. The final molecule acceptor of the electron transport chain is CoQ. d. Chemiosmosis refers to the synthesis of ATP due to the DG.

45. Choose the correct answer. a. Fructose is an epimer of glucose. b. Glucose is a disaccharide. c. Glucose and galactose are epimers. d. Lactose is a polysaccharide. e. Amylopectin enters only in the structure of glycogen.

46. Choose The false Answer. a. Oxaloacetate is regenerated to every loop of the Krebs Cycle. b. The TCA cycle is an anaerobic pathway. c. The reduced coenzyme NADH and FADH2 from Krebs cycle will be oxidized in the electron transport chain. d. Acetyl-coenzyme A is transformed in CO2 in Krebs cycle. e. NADPH which is required for cell detoxification is produced in pentose phosphate pathway.

47. Choose The false Answer. a. Gluconeogenesis provides the body with adequate glucose level when liver glycogen is depleted. b. Between liver and muscle, it is the Cory cycle which functions in anaerobic conditions. c. Gluconeogenesis is stimulated under the effect of insulin. d. The substrates for synthesis of glucose are lactate, private and glycerol. e. During gluconeogenesis ATP is consumed.

48. Choose the correct answer. a. The Exergonic process is a process in which the DeltaG is less than 0. b. AMP is a high-energy molecule. c. Carbonyl Phosphate is not a high-energy molecule. d. A system is in equilibrium when DeltaG is less than 0. e. Macrogenic bond is formed when energy is released.

49. Which molecule will combine with the four Carbon in Krebs-Cycle to form six-carbon citrate?. a. NadH. b. AcetylCoA. c. Lactic Acid. d. FadH.

50. During producing starvation which of the following hormones is responsible increasing glycogenesis in the liver?. a. Insulin. b. TSH. c. glucagon. d. tyrosine. e. GH.

51. Which of the following is most important for the maintenance blood glucose level during early stages of a fast?. a. Brain. b. Adipose tissue. c. muscle. d. liver.

52. The transamination of the Alanine directly yields?. a. Pyruvate. b. Glucose. c. Thyroxine. d. Glutamate. e. Oxaloacetate.

53. Which of the following sentences about the digestion of ______ is correct?. a. Protein digestion begins in the small intestine. b. Protein digestion begins in the stomach. c. Protein digestion begins in the mouth. d. Protein digestion begins when the hydrochloric acid first hydrolyses the peptide bonds. e. Protein digestion begins when trypsinogen has been activated to trypsin by hydrochloric acid.

54. For every NADH2 that enters the electron transport system: ____ ATP result. a. 1. b. 2. c. 3. d. 5. e. 10.

55. Salivary amylase is active in which of the following parts of the digestive system?. a. Liver. b. Small Intestine. c. Mouth. d. Stomach. e. Pancreas.

56. Within the cytoplasm of hepatocytes, bilirubin is conjugated with: a. UDP. b. glucose. c. albumin. d. Glucuronic Acid. e. Ferritin. f. Plasma Enzymes.

57. Citric acid cycle occurs in: a. Cytoplasm. b. Endoplasmic reticulum. c. Mitochondria. d. Golgi bodies. e. Cell Membraned.

58. The precursor for fatty acid synthesis is: a. Acetyl CoA. b. Propionyl CoA. c. Succinyl CoA. d. Acetoacetyl CoA. e. Acyl CoA.

59. The transfer of an amino group from one amino acid to an a-keto acid is called. a. Transamination. b. Deamination. c. Reamination. d. Examination. e. Phosphorylation.

60. Choose the correct answer: a. Seliwanoffs Test is used to identify plasma proteins. b. Fehlings Test is used to identify phosphorus. c. Serum proteins form a complex with copper in an alkaline solution. d. Plasma proteins decrease the pH of the body. e. Glucose is the most abundant component in the body.

61. If two FADH2 molecules are produced in the Krebs cycle, how many total ATP molecules will be formed as those hydrogens are transmitted to the electron transport system?. a. 2. b. 4. c. 6. d. 8. e.10.

62. Calcium/Phosphate levels in the blood are regulated by: a. Aldosterone. b. Cortisol. c. ACTH. d. PTH & calcitonin. e. T3 & T4.

63. Choose the correct answer: a. The Majority of the chloride ion in the body is found in the intracellular fluid compartment. b. Dietary iron is stored within a protein complex called ferritin. c. Magnesium is the main abundant material in the body. d. Magnesium ion functions along with sodium ion (NA+) and potassium ion (K+) in the maintenance of electrolyte balance. e. Iron homeostasis requires ascorbic acid which inhibits the absorption of dietary iron.

64. The major storage of lipids is: a. esterified cholesterol. b. glycerophospholipid. c. triglyceride. d. sphingolipid.

65. Antioxidant defence contains, except: a. ATP Synthase. b. Glutathione peroxidase. c. Vitamin C. d. Glutathione -Superoxide Dismutase.

67. The main function of pentose phosphate pathway is: a. Supply NADP+. b. Supply NADH. c. Supply energy. d. Supply pentoses and NADPH. e. Supply Hexoses.

68. How many times does the Krebs cycle turn per glucose molecule?. a. once. b. twice. c. three times. d. four times. e. five times.

69. Which molecule will combine with the four-carbon oxaloacetate in the Krebs cycle to form the six-carbon citrate?. a. Two carbon dioxide molecules. b. Lactic acid. c. Acetyl-CoA. d. NADH. e. FADH2.

70. Choose the false answer: a. The transaminases are involved in the transfer of an amino group from a 2-amino- to a 2-oxoacid. b. The transaminases need the cofactor, pyridoxal phosphate for optimal activity. c. Measurement of transaminases is useful for the diagnosis of bone diseases. d. The level of transaminases is elevated in blood as a result of a leakage from damaged cells. e. De Ritis ratio is referred to AST/ALT.

71. The transamination of the alanine directly yields: Pyruvate. Glucose. Tyrosine. Oxaloacetate. Glutamate.

72. Which of the following statements is NOT correct when ... catabolism?. The carbon skeleton of amino acids is produced in the liver. During deamination of an amino acid, the carboxyl group is. The amino group becomes ammonia. Ammonia enters the urea cycle and becomes part of urea. -Urea is the primary excretory product of humans.

73. Choose the false answer: The physical characteristics of urine include observations and measurements of color, turbidity, odor, pH and volume. Hemoglobin is normally absent in the urine. In urine are present proteins, glucose and fatty acids normally. Creatine is excreted in the urine. In urine are presented proteins, glucose and fatty acids only pathological.

74. Urea is the end product of the____ reactions: Krebs cycle. Gluconeogenesis. Glycolysis. Proteins digestion. Urea cycle.

75. During each cycle of B-oxidation: One carbon atom is removed from the carboxyl end of fatty acid. One carbon atom is removed from the methyl end of fatty acid. Two carbon atoms are removed from the carboxyl end of fatty acid. Two carbon atoms are removed from the methyl end of fatty acid. Two carbon atoms are added to the carboxyl end of fatty acid.

76. Choose the correct answer: Urea represents the end of chain of reactions which break down the fatty acids that make up proteins. Glucose is transported in the blood as lipoprotein. The terminal product of fatty acids metabolism. Most part of the excreted waste nitrogen is in the form of urea which is produced in the liver. Excess circulation and accumulation of bilirubin results in a pink discoloration of the tissues.

77. What molecule will form when hydrogen ions flow down the electrochemical gradient through ATP synthase complexes in mitochondria?. Water. ATP. ADP. Carbon Dioxide. Oxygen.

78. Which of the following statements is true about Cori-Cycle (lactate-glucose): The Cori Cycle involves three tissues muscle, brain, and liver. It involves transport of lactate from liver to skeletal tissue for gluconeogenesis.

79. Which of the following statements about food storage in the body is correct?. a. More glycogen is stored per unit mass in the muscles than in the liver -Glycogen storage in the liver is unlimited. Fat is a more efficient form of fuel storage than glycogen. Proteins in muscle cells are a normal storage form of fuel. All of these.

80. Hormone-sensitive lipase is regulated by the action of the hormones: Insulin and noradrenaline. Thyroxine and vasopressin. Glucagon and calcitonin. Steroidal Hormones. Growth Hormone.

81. Which of the following statements about the use and synthesis of glucose in the body is correct?. Brain can use fatty acids for all its energy needs. Red blood cells can use fatty acids for all their energy needs. The brain can use ketone bodies for all its energy needs. The brain can use glucose for all its energy needs. Red blood cells can use amino acids for all their energy needs.

82. Which coenzyme is used in cellular respiration. NADP. Alcohol dehydrogenase. ATP. NAD+.

83. Which of the following pathways and reactions will result in the production of the most ATP molecules during aerobic cellular respiration of one glucose molecule?. Glycolysis. Citric Acid Cycle. Electron transport chain. Break down of Pyruvate.

84. Each cycle of b-oxidation produces. 1 FAD, 1 NADH, and 1 acetyl-CoA. 1 FADH2, 1 NADH, and 1 acetyl-CoA. 1 FAD, 1 NAD+, and 2 CO2 molecules. FADH2, 1 NAD+, and 1 acetyl-CoA.

85. A general process that breaks down large molecules into smaller ones is called: metabolism. dehydration. catalysis. catabolism.

86. Free fatty acids in the plasma. Circulate in the unbound state. Bind to lipoproteins and circulated. Bind to albumin and circulated. Bind to a fatty acid-binding protein and circulated.

87. What is the precursor for fatty acid synthesis?. Acetyl CoA. Propionyl CoA. Succinyl CoA. Acetoacetyl CoA.

88. Long-chain fatty acids are oxidized step-wise in __2__carbon units starting from the __carboxyl__end. ,. m.

89. The acyl-CoA formed in the cytosol is transported to the ___ for oxidation using a shuttle involving the intermediate formation of acyl- _____. mitochondrial matrix, Carnitine. mitochondrial matrix, coenzyme A. endoplasmic reticulum, albumin. endoplasmic reticulum, carnitine. microsomes, Coenzyme A.

89. Choose The false Answer. Oxaloacetate is regenerated to every loop of the Krebs Cycle. The TCA cycle is an anaerobic pathway. The reduced coenzyme NADH and FADH2 from the Krebs cycle will be oxidized in the electron transport chain. Acetyl-coenzyme A is transformed in CO2 in the Krebs cycle. NADPH which is required for cell detoxification is produced in the pentose phosphate pathway.

90. Which of the following is most important for the maintenance blood glucose level during early stages of a fast?. Brain. Adipose tissue. Skeletal muscle. Liver.

91. The synthesis of complex molecules by using simple precursors of smaller units is names as: Catabolism. Anabolism.

92. primary storage site for glycogen is. liver and heart. liver and brain. liver and skeletal muscle. brain and heart.

93. in which cellular compartment glycogenesis occurs. matrix of mitochondria. cytoplasm. intermembrane space of mitochondria. cytosol.

93. Glycogenesis is initiated by. glucose. glycogenin. glucose 6 phosphate. UDP glucose.