Biochem

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TEST QUESTIONS IN BIOCHEMISTRY

NUTRITION - 30

I. Given patient data, determine the metabolic pathways and processes involved.

1. A two year old boy, short for his age, presented with leg edema and abdominal swelling. He was weaned from breast milk at one year of age, because of the coming of another baby. He was fed rice or lugaw everyday mixed with condensed milk. The edema is caused by:

A. lack of protein in his diet B. excessive intake of water C. kidney failure

D. presence of intestinal parasites Recall

Answer: A. lack of protein in his diet

Reference: Harper's Illustrated Biochemistry 27th_{ed., Murray, Granner & Rodwell}

2006 The MacGraw-Hill Companies, Inc., p. 241, par. 1, p. 487, par. 3 2. Catabolism of amino acids requires the participation of transaminase enzymes. What

coenzyme form of vitamin B is an important participant in this reaction? A. thiamin pyrophosphate

B. nicotinamide adenine dinucleotide C. tetrahydrofolic acid

D. pyridoxal phosphate Recall

Answer: D. pyridoxal phosphate

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 247 par. 2 , p. 498 - 499}

3. In marasmus, the affected person has very little fat reserves and there is wasting of muscles. The person is said to be in :

A. positive nitrogen balance B. negative nitrogen balance C. nitrogen balance

D. equilibrium Recall

Answer: B. negative nitrogen balance

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 487 par. 3}

4. Persons who consume large amounts of unleavened whole-wheat products may experience calcium deficiency because:

A. wheat is poor in calcium

B. wheat contains phytic acid which prevents calcium absorption C. the wheat is deficient in vitamin D

D. absorbable form of calcium is not generated Application

Answer: B. wheat contains phytic acid which prevents calcium absorption Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 485 par. 5}

5. An elderly woman is believed to be suffering from vitamin B12 deficiency. Which of the following can be the basis for this statement?

A. she has been diagnosed to be deficient in cobalt B. she is a vegan

C. she has methylmalonic aciduria D. any of the above

Application

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6. The patient was in coma. Since diabetes was ruled out, how does one explain the condition? A. patient has ammonia intoxication because of the liver pathology

B. coma is due to marked ketosis

C. acid-base balance of the patient is disturbed D. there is increase urea production

Application

Answer: A. patient has ammonia intoxication because of the liver pathology Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 248 par. 4}

7. The obese matron was instructed by her physician to alter her diet and eat only protein foods to bring down her weight. The matron was afraid however that the absence of carbohydrates in her meals will cause hypoglycemia and give her more problems. The physician was certain she does not have to worry about this because:

A. she's going to cheat on her diet anyway

B. the excess body fat will be converted to glucose C. amino acids in excess are converted to glucose D. she has a lot of glycogen slores

Application

Answer: C. amino acids in excess are converted to glucose

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 172 par. 2, p. 175 summary,}

p. 269 summary

II. Given a patient with a nutritional deficiency, give the expected clinical manifestation 8. Deficiency of iron results in which of the following?

A. failure to metabolize proteins

B. heme-containing enzymes remain inactive C. there is liver dysfunction

D. individual goes into ATP production using fats Recall

Answer: B. heme-containing enzymes remain inactive

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 504 Table}

9. An infant with genetic deficiency of glucose-6-phosphatase also known as von Gierke's disease will exhibit this clinical sign:

A. poor exercise tolerance B. muscle dystrophy

C. hypoglycemia & lactic acidemia D. glycogen with few branch points Recall

Answer: C. hypoglycemia & lactic acidemia

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 166 Table}

10. In the absence of creatine kinase enzymes, an athlete would have problem in: A. oxidizing creatine

B. releasing ATP from biological oxidation C. aerobic glucose oxidation

D. generating ATP reserves for muscle contraction Recall

Answer: D. generating ATP reserves for muscle contraction Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 583 par. 1-3}

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11. A young woman already in her fifth month of a carbohydrate and lipid-free diet was advised by her physician to increase the amount of fats in her diet because she appears to be suffering from vitamin A deficiency despite her regular vitamin intake. Which of the following complaints presented by the woman supports the diagnosis?

A. she has lesions of the corner of the mouth B. her wounds take longer time to heal

C. she finds it hard to see in the dark when in a movie theater D. she has this sensation of "burning feet".

Application

Answer: C. she finds it hard to see in the dark when in a movie theater Reference: Harper's Illustrated Biochemistry, 27th_{edition, p. 491, par. 4, line 3}

12. Tests done on a two month-old baby showed deficiency in enzymes of the Uronic Acid Pathway. What clinical manifestation may be observed?

A. elevated urinary glucuronic acid B. yellow coloration of the skin

C. high direct-reacting bilirubin in plasma D. accumulation of heme

Application

Answer: B. yellow coloration of the skin

Reference: Harper's Illustrated Biochemistry, 27th_{edition, p. 289 par. 2, p. 290 par. 2}

13. A 35 year old Muntinlupa inmate was confined to 6 weeks of isolation because of bad behavior. Although he was given regular meals, he stayed in the underground cell for the duration of the 6 weeks. If the prisoner became deficient in vitamin D because of this, what signs should the attending physician look for? in the inmate:

A. there may be kidney stones formation B. the inmate may complain of tiredness C. he can easily be fractured

D. serum calcium will be extremely low Application

Answer: C. he can easily be fractured

Reference: Harper's Illustrated Biochemistry, 27th_{edition, p. 492 - 493}

14. Thiamine deficiency can result in Wernicke- Korsakoff's syndrome. The absence of the vitamin prevents the conversion of pyruvate to acetyl CoA on a high carbohydrate diet. Which compound would be found to be high in concentration in the plasma?

A. glucose

B. lactate & pyruvate C. acetyl CoA

D. alcohol Application

Answer: B. lactate & pyruvate

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III. Given a laboratory finding, identify the involved biochemical mechanism

15. Important in the synthesis of collagen, this vitamin serves as cofactor of the mixed function oxygenase enzymes, proline & lysine hydroxylases:

A. vitamin B1 B. vitamin B2 C. vitamin C D. folic acid Recall Answer: C. vitamin C

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 242 par. 3, line 9}

16. Unlike other vitamins, niacin is a semi-essential vitamin because it can be synthesized from this amino acid:

A. proline B. phenylalanine C. tryptophan D. histidine Recall Answer: C. tryptophan

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 498, par. 1}

17. Activity of the aldose reductase enzyme in the lens of the eye increases in the presence of high concentration of glucose. This initiates the conversion of glucose to a compound that has been linked to osmotic damage and cataract formation. What compound is this?

A. mannitol B. galactitol C. ribitol D. sorbitol Recall Answer: D. sorbitol

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 185 last par.}

18. A patient was tested for transketolase activity of the erythrocyte lysate. Results showed markedly low activity of the enzyme, consistent with the physicians impression of deficiency of this vitamin: A. vitamin B2 B. vitamin B3 C. vitamin B5 D. vitamin B1 Application Answer: D. vitamin B1

19. Inorganic iron is best absorbed by the body in the ferrous form. What is the rationale behind the addition of vitamin C in many iron preparations?

A. vitamin C can take the place of iron B. absorption of other minerals is prevented C. vitamin C chelates iron

D. vitamin C keeps the iron in reduced (ferrous) state Application

Answer: D. Vitamin C keeps the iron in reduced (ferrous) state Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 485 - 486}

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20. In a routine medical check up, an executive showed elevated plasma levels of lactic acid dehydrogenase enzymes 1 & 2 and low levels of LDH 5. This prompted his physician to refer him to a cardiologist because:

A. low levels of LDH 5 indicated a clogged vessel B. it is part of the medical check up

C. increase levels of LDH 1 & 2 is indicative of myocardial infarction D. angioplasty was needed

Application

Answer: C. increase levels of LDH 1 & 2 is indicative of myocardial infarction Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 57}

21. A tourist from the Caribbean fell ill and was diagnosed to have malaria. He was given primaquine upon admission to the hospital and was thought to be recuperating when he showed signs of hemolytic anemia. Tests showed he had glucose 6- phosphatase deficiency. What is the biochemical explanation for the hemolysis?

A. the malarial parasite had invaded the rbc

B. inactivity of the Hexose Monophosphate Shunt prevented the NADPH - reduction of membrane glutathione

C. the drug oxidized membrane proteins

D. absence of G6PD initiated release of peroxides

Application

Answer: B. inactivity of the Hexose Monophosphate Shunt prevented the NADPH - reduction of membrane glutathione

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 177 par. 2, p. 183 par. 2}

V. Given patient data, formulate an appropriate nutritional plan

22. Metabolic screening of a newborn showed absence of galactose uridyltransferase enzyme. What should be the dietary recommendation?

A. Galactose should not be included in the diet

B. Galactose - free and lactose -free milk should be given C. Newborn should be breastfed

D. Liquid protein preparation instead of milk should be given Recall

Answer: B. galactose-free and lactose -free milk should be given Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 186 par. 2}

23. A born-again vegetarian was diagnosed to be suffering from vitamin B12 deficiency. Which of the following suggestions should be followed?

A. the vegetarian should include meat in the diet B. he should be tested for pernicious anemia

C. the born-again can take in vitamin B12 preparation to meet the requirement

D. intrinsic factor should be released from bonding Recall

Answer: C. the born-again can take in vitamin B12 preparation to meet the requirement

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 499 - 500}

24. A woman had just given birth by ceasarean section. For fast recuperation she should be advised to:

A. eat nutritious and protein-rich foods B. rest in bed until the incision heals C. include more carbohydrates in the diet D. drink a lot of water

Recall

Answer: C. eat nutritious and protein-rich foods

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25. A 50 year old male is suffering from gout because of his tendency to over eat. He should be told to:

A. eat moderately

B. stay away from nuclei-rich foods like nuts, beans, meat C. drink plenty of water

D. all of the above Recall

Answer: D. drink plenty of water

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 307 par. 2 & 3}

Questions # 26-28

A 32 year old married woman consulted at the OPD because of increasing thirst and frequent urination. She is 5 feet 2 inches tall and weighs 168 lbs.

26. Which of the following statements best described the metabolic status in this patient? A. Her energy expenditure is greater than food intake hence she is diuresing B. She is obese and she has increased mortality

C. The (BMR) basal metabolic rate of this patient is higher compared to a man of the same body weight

D. She is frequently urinating because she has increased protein reserves Application

Answer: B. She is obese and she has increased mortality Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 486}

27. The BMI of the patient is:

A. 25 B. 27 C. 29 D. 31 Application Answer: D. 29

28. You want to give this patient a 1,500 cal/day diet because you want her to lose weight. How do you formulate an appropriate plan for this patient?

A. Carbohydrate - 55% Fats = 35% Protein = 10% B. Carbohydrate - 30% Fats = 20% Protein = 50% C. Carbohydrate - 0% Fats = 40% Protein = 60% D. Carbohydrate - 40% Fats = 40% Protein = 20% Application

Answer: A. Carbohydrate - 55% Fats = 35% Protein = 10%

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 132}

29. The edema of a patient with kwashiorkor should respond best when prescribed with: A. diet rich in protein

B. diuretics C. bed rest

D. virgin coconut oil Application

Answer: A. diet rich in protein

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30. A 32 year old physician suffered a 3rd_{degree burn. He stayed in the hospital for almost one}

month. What can be said of his metabolic condition

A. the excretion of nitrogenous compounds is less than the dietary intake B. negative nitrogen balance

C. positive nitrogen balance

D. there is net retention of the nitrogen in the body as protein Application

Answer: B. negative nitrogen balance

METABOLISM - 40

I. Given patient data, determine the metabolic pathways and processes involved.

31. The human body, even at rest, uses up energy. This amount of energy expenditure is termed as:

A. Respiratory Quotient B. Basal Metabolic Rate C. Respiratory Burst D. Body Mass Index Recall

Answer: B. Basal Metabolic Rate

32. Uptake of glucose in these tissues is controlled by the hormone insulin: A. liver & kidneys

B. adipose tissue & muscle C. muscle & intestines D. liver & rbc

Recall

Answer: B. adipose tissue & muscle

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 140, par. 3, line 1}

33. Between meals, the blood glucose concentration of the body is maintained through these metabolic pathways:

A. glycolysis & gluconeogenesis B. glycogenesis & glycogenolysis C. glycolysis & glycogenolysis

D. glycogenolysis & gluconeogenesis Recall

Answer: D. glycogenolysis & gluconeogenesis

34. During continuous anaerobic physical activity, e.g. when working out in a gym, this metabolic pathway is used by the muscles

A. gluconeogenesis B. glycolysis

C. Hexose Monophosphate Shunt D. glycogenesis

Recall

Answer: B. glycolysis

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35. When tested, a young woman, complaining of fatigability and poor exercise tolerance was found to have only one sixth the amount of carnitine found in others who had no muscle disease. This means that the above symptoms she is experiencing is due to:

A. inability of the body to synthesize lipids B. inhibition of ATP production

C. failure of fatty acids to enter - oxidation D. impairment of the mitochondria

Recall

Answer: C. failure of fatty acids to enter - oxidation

36. Newborn infants can generate more heat needed by the body because they contain thermogenin, an uncoupling protein. This protein exerts its effect by:

A. increasing the amount of substrate oxidized B. preventing heat loss

C. dissociating respiratory chain oxidation from ATP synthesis (phosphorylation) D. activating respiratory chain enzymes

Application

Answer: C. dissociating respiratory chain oxidation from ATP synthesis (phosphorylation)

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 107, par. 4, p. 228 - 229}

37. Erythrocytes are hemolyzed when there is impairment of the Pentose Phosphate Pathway and this is manifested in a person as hemolytic anemia. This defect is due to:

A. lack of NADPH from the Pentose Phosphate Pathway B. non-synthesis of ATP

C. failure to release ribose

D. defect in the membrane transport Application

Answer: A. lack of NADPH from the Pentose Phosphate Pathway Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 183- 184, par. 1}

38. A 30 year old patient was diagnosed to be suffering from a mitochondrial disease that specifically involves defect in mitochondrial energy transduction.

Which of the following signs/symptoms will be evident?

A. High body mass index (BMI), hyperactivity, increased appetite B. Hyperventilation, clammy sweat

C. Muscle weakness, excessive perspiration, and elevated BMR (Basal metabolic rate)

D. lack of appetite, hypoventilation Application

Answer: C. Muscle weakness, excessive perspiration, and elevated BMR (Basal metabolic rate)

39. A newborn infant tested positive in the phenylketonuria screening. The attending pediatrician ordered a change in the infant milk to one which contains negligible amount of:

A. lactose B. proteins C. fats D. glucose Application Answer: B. proteins

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40. A drug used as an adjunct in the treatment of obesity inhibits pancreatic lipase. Following its intake, which of the following is expected to be excreted in great amount in the feces? A. cholesterol

B. triacylglycerols C. free fatty acids D. bile salts Application

Answer: B. triacylglycerols

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 483, par. 4, p. 484 diagram}

II. Given a patient with a nutritional deficiency, give the expected clinical manifestation 41. In the mucopolysaccharidoses, glycosaminoglycans are not degraded due to the absence of

lysosomal hydrolases. Individuals suffering from this can be identified because of: A. excessive accumulation and urinary excretion of the proteoglycans

B. presence of enzyme fragments in the urine C. release of the core proteins in urine

D. increase turnover of affected cells Recall

Answer: A. excessive accumulation and urinary excretion of the proteoglycans Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 555 par. 5}

42. In the rare disease, analbuminemia, there is complete lack of serum albumin. The affected individual presents with this:

A. extreme edema

B. edema & presence of free fatty acids C. accumulation of triglycerides

D. elevated plasma cholesterol Recall

Answer: B. edema & presence of free fatty acids

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 592 par. 1, p. 187 par. 3}

p. 711 Clinical Correlation , Textbook of Biochemistry, 5th_{ed., Thomas Devlin,}

editors, 2002 Wiley-Liss

43. Metabolic screening was requested for a week-old newborn because the grandmother had noticed the dark stains on the wet diaper whenever she attended the infant. Tests identified the condition as alkaptonuria. What urinary metabolic should the physician request in the laboratory tests? A. tryptophan B. tyrosine C. homogentisic acid D. melanin Recall

Answer: C. homogentisic acid

Reference: Harper's Illustrated Biochemistry 27th_{ed., p.259 par. 2}

Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 801, Clinical Correlation}

44. Skeletal muscles do not have the enzyme glucose-6-phosphatase. This means: A. they cannot degrade glucose

B. glucose cannot be synthesized C. ATP cannot be generated D. glycogen is stored in big amount Recall

Answer: B. glucose cannot be synthesized

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45. L-xylulose reductase catalyzes the reduction of xylulose to xylitol. In affected individuals, absence of this enzyme results in:

A. formation of cataracts

B. failure to synthesize nucleic acids

C. excretion of large amounts of urinary pentose D. presence of skeletal deformities

Recall

Answer: C. excretion of large amounts of urinary pentose

46. When there is restricted intake of carbohydrates as in starvation and uncontrolled diabetes mellitus, ketosis results because of:

A. change in pH of the body B. failure to oxidize glucose C. mobilization of fatty acids D. inactivity of buffer systems Application

Answer: C. mobilization of fatty acids

Reference: Harper's Illustrated Biochemistry, 27th_{ed., p. 194 last par. , p.195 , 2}nd_par.

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47. Measurement of HbA1c or glycosylated hemoglobin provides valuable information for the management of diabetes mellitus because it:

A. is elevated in diabetes mellitus

B. reflects the mean glucose concentration over the preceding 6 - 8 weeks C. is formed by reaction with HbA

D. is released when rbc dies Application

Answer: B. reflects the mean glucose concentration over the proceeding 6 - 8 weeks Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 48, par.1}

48. Inherited enzyme deficiencies of the Krebs-Henseleit cycle always present with this observation:

A. increase urea production

B. formation of organic metabolites C. ammonia intoxication

D. depletion of citrulline Application

Answer: C. ammonia intoxication

49. The urine-soaked diaper of a week old baby was noted by the mother to smell like burnt sugar. Her concern turned into worry when the pediatrician told her the baby may be suffering from maple syrup urine disease. To confirm this, activity of the keto acid decarboxylase complex has to be measured. Which amino acids will have increased concentration in plasma and urine?

A. serine, threonine & hydroxyproline B. cysteine, cystine, methionine C. valine, leucine & isoleucine D. glycine, alanine & asparagine Application

Answer: C. valine, leucine & isoleucine

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50. Calcium deficiency manifestations may also be seen in people who consume: A. large amounts of unleavened whole wheat products

B. high concentrations of fatty acids C. high amounts of oxalates

D. all of the above Application

Answer: A. large amounts of unleavened whole wheat products Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 265, par. 2}

III. Given a laboratory finding, identify the involved biochemical mechanism

51. Milk intolerance, common among Asian populations and characterized by an osmotic type of diarrhrea following the intake of milk is attributed to deficiency of:

A. pancreatic amylase B. lactase C. sucrase D. maltase Recall Answer: B. lactase

52. Rate-limiting reaction in cholesterol synthesis which is inhibited by the "statins" group of drugs is catalyzed by this enzyme:

A. cholesterol esterase B. squalene cyclase C. mevalonate kinase

D. beta hydroxyl-beta methyl glutaryl CoA reductase Recall

Answer: D. beta hydroxyl-beta methyl glutaryl CoA reductase Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 231, par. 2}

53. All the carbon atoms of cholesterol are synthesized from this common metabolite: A. alanine

B. acetyl CoA C. glucose D. palmitate Recall

Answer: B. acetyl CoA

54. Carbohydrates, lipids & proteins can be oxidized to acetyl CoA or specific metabolites intermediates using a final common pathway. The pathway functions in gluconeogenesis, lipogenesis and interconversion of amino acids. This pathway is known as:

A. Glycolysis

B. Hexose Monophosphate Shunt C. Citric Acid Cycle

D. Glucuronic Acid Pathway Recall

Answer: C. Citric Acid Cycle

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55. In the capillaries, hemoglobin releases oxygen and accepts carbon dioxide. The process generates protons e which can then lower the blood pH. The buffering action of hemoglobin will prevent this from taking place. What amino acid residues in hemoglobin are most important in this shift in pH buffering effect at normal blood pH?

A. arginine B. lysine C. histidine D. glutamate Recall Answer: C. histidine

56. The highest number of energy released as ATP is obtained by complete oxidation of this compound to carbon dioxide and water

A. an amino acid B. a triglyceride C. glucose D. a nucleic acid Application Answer: B. a triglyceride

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 142, table 16-1, p.189, par.1}

57. Laboratory tests done on a 3 year old boy showed excessive nucleic acid bases in the urine and negligible activity of HGPRTase. Which statement explains the results obtained?

A. purine bases are very insoluble

B. low enzyme activity is due to feedback inhibition

C. Salvage pathway of synthesizing nucleotides is inactive D. young cells utilize the in vivo method for synthesis Application

Answer: C. Salvage pathway of synthesizing nucleotides is inactive Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 308, par. 1}

58. In myocardial infarction where a major coronary artery is occluded, ischemia results and a lowered oxygen supply diminishes the amount of ATP available in the cell. This effect on cellular energy is due to:

A. release of enzymes

B. lack of oxygen which slows down the mitochondrial electron transport chain C. inhibition of substrate level phosphorylation

D. kind of occlusion Application

Answer: B. lack of oxygen which slows down the mitochondrial electron transport chain

Reference: Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 591, Clinical Correlation}

59. The patient was diagnosed to be suffering from megaloblastic anemia. Results of urinary tests showed 10 mg of formiminoglutamic acid (FIGLU), making the physician conclude that the patient has folic acid deficiency. Which statement explains the diagnosis given?

A. megaloblastic anemia is a unique feature of folic acid deficiency

B. transfer of formimino group of histidine to tetrahydrofolate does not take place and figlu is excreted

C. figlu is a metabolite of folate

D. one carbon compounds are carried by folic acid Application

Answer: B. transfer of formimino group of histidine to tetrahydrofolate does not take place and figlu is excreted

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60. In the glycogen storage disease, McArdle's disease, muscle phosphorylase is absent. Patients who suffer from this will therefore show the following signs:

A. inability to perform strenuous exercise because glycogen cannot be degraded B. there is no increase in plasma lactic acid

C. no energy supply for the muscles D. all of the above

Application

Answer: D. all of the above

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 582,}

Textbook of Biochemistry, 5th_{ed., Thomas Devlin editors, 2002 Wiley-Liss}

p. 647

V. Given patient data, formulate an appropriate nutritional plan

61. A person is suffering from gouty arthritis. What foods should not be included in his daily meals?

A. peas, legumes and beans family B. meat and internal organs

C. strawberries, cauliflower, broccoli D. all of the above

Recall

62. What foods, cheap but rich in proteins, can the physician suggest to patients from the low income group?

A. pork ribs and pork legs B. milk and cheese

C. anchovies, bean sprouts, mung beans D. instant noodles

Recall

Answer: C. anchovies, bean sprouts, mung beans

63. Patient has been found to be deficient in vitamin E. Which of the following should he included in his market list as source of vitamin E?

A. salmon fish B. beans C. alfalfa D. oats Recall Answer: C. alfalfa

64. An elderly woman insists that the house help cook sweetened oatmeal, with milk, every morning for her breakfast, without fail. This makes the elderly woman feel good and it is a complete food according to her because it has:

A. protein

B. fiber for her constipation C. sugar as energy source D. all of the above

Recall

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65. What advice can a physician give to someone who has problems with bowel movement and is always constipated.

A. drink plenty of water

B. eat foods rich in fiber e.g. whole wheat , bran, oats C. include vegetables with high fiber

D. all of the above Recall

Answer: C. include vegetables with high fiber

Reference: Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 1127}

66. A mother brought her 8 month old, 6 kg baby to a Health Center because of diarrhea of one day duration which occurred 4 times. The baby had been breast-fed since birth and "lugaw" with fish and vegetables were started at 5 months. Breast feeding was stopped at the onset of the diarrhea and the baby was given "am" with sugar instead. What suggestion can be given to the mother to improve the overall condition of her child?

A. meat and more solid foods can be given

B. giving "am" with sugar, and a little salt can be used for diarrhea C. breastfeeding should continued even when there is diarrhea D. all of the above

Application

67. What is the so called oral rehydration therapy for cases of diarrhea developed by the World Health Organization?

A. daily ingestion of 8 glasses of water B. oral isotonic NaCl solution

C. intake of a NaCl and glucose oral mixed preparation D. daily intake of sucrose solution

Application

Answer: C. intake of a NaCl and glucose oral mixed preparation

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 436, last paragraph}

68 - 70 After an all night drinking spree with friends, 45 year old Juan woke up with pain all over, but mainly of the lower extremeties. His arthritis worsens everytime he goes drinking. Earlier he had been advised by his physician to take thiamine because he seems to be exhibiting symptoms of the Wernicke-Korsakoff syndrome.

68. What is the importance of taking thiamine in this case?

A. ensures complete metabolism of carbohydrates and the alcohol B. the arthritic pain will be relieved

C. this is a cure for the symptoms of the syndrome D. thiamine is a cofactor of alcohol dehydrogenase Application

Answer: A. ensures complete metabolism of carbohydrates and the alcohol Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 496 par. 2}

69. What enzyme of carbohydrate metabolism is activated by vitamin B1? A. alcohol dehydrogenase

B. pyruvate dehydrogenase C. pyruvate kinase

D. phosphoenol pyruvate kinase Application

Answer: B. pyruvate dehydrogenase

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70. To alleviate the arthritic pain, what suggestion on dietary habits should the physician give Juan in addition to staying away from alcohol?

A. eat plenty of fats for energy source

B. take hypouricemic drugs, eat minimal amount of meat, and drink a lot of water C. stay away from fruits and vegetables

D. include nucleic acid rich foods in the meals Application

Answer: B. take hypouricemic drugs, eat minimal amount of meat, and drink a lot of water

Reference: Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 834}

GENETICS - 15

I. Given patient data, determine the metabolic pathways and processes involved 71. Patients with hyperuricemia experience pain because of the insolubility of uric acid.

Physicians prescribe allopurinol, a structural analog of purines. Levels of uric are lowered through this mechanism:

A. non-competitive inhibition of purines B. allopurinol increases solubility of uric acid

C. uric acid is degraded in the presence of allopurinol D. competitive inhibition of xanthine oxidase

Recall

Answer: D. competitive inhibition of xanthine oxidase

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 298 par. 4 line 11}

72. Cytosine arabinoside is an anti metabolite used in the treatment of some forms of cancer. It is a structural analog of dCTP. Its effectivity as an anti-cancer compound is due to the following: A. competes with dCTP for incorporation to DNA

B. inhibits DNA polymerase C. binds to ribose sugars D. degrades cancer cells Recall

Answer: A. competes with dCTP for incorporation to DNA

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 298 par. 4 line 13}

Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 854 par. 6}

73. Methotrexate, an anti cancer drug, is a structural analog of folic acid. Its effective anti-cancer action is attributed to its:

A. inhibiting DNA elongation B. complexing with thymine

C. inhibition of the dihydrofolate reductase enzyme D. precipitation of DNA

Application

Answer: C. inhibition of the dihydrofolate reductase enzyme Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 304, par. 4}

74. In one type of hemoglobin structure, base A of a codon was changed to base U. What possible results can happen?

A. newly formed codon may dictate the same amino acid B. the new hemoglobin is a mutant

C. oxygen carrying capacity of hemoglobin may change D. all of the above

Application

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75. The thalassemias involve defects in the synthesis of globin chains, involving either genetic deletion or frameshift mutation in the synthesis of the messenger RNA. Which of the following will not be an effect of the genetic defect?

A. reading frame of DNA chain will change B. a functional globin chain will be coded C. change in code carried by mRNA D. individual will present with anemia Application

Answer: B. a functional globin chain will be coded

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 47 - 48}

Textbook of Biochemistry, 5th_{ed., Thomas Devlin, p. 224 Clinical Correlation}

IV. Given a clinical condition, identify the genetic/immunologic processes involved 76. . Xeroderma pigmentosa is a genetic disease characterized by the individual's marked

sensitivity to sunlight. The defect lies on: A. mutant helicases

B. DNA ligase

C. nucleotide-excission repair process D. the DNA polymerase

Recall

Answer: C. nucleotide-excision repair process

77. Sickle cell disease is a classic example of a point mutation causing a structure abnormality of the - globin gene. This results in this amino acid change:

A. valine instead of glutamic acid B. leucine instead of glycine C. lysine instead of aspartate D. tyrosine instead of alanine Recall

Answer: A. valine instead of glutamic acid

78. The tetracycline drugs work by preventing the binding of amino acyl tRNAs to the A site of the bacterial ribosome. This will result in:

A. inhibition of bacterial replication B. bacterila cell lysis

C. activation of transcription D. inhibition of protein synthesis Recall

Answer: D. inhibition of protein synthesis

79. A newly-launched antibiotic, is credited with inhibiting the DNA helicase which then stops the synthesis of proteins in bacterial systems. At what stage of protein synthesis does the antibiotic act? A. replication B. transcription C. translation D. reverse transcription Recall Answer: A. replication

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80. Menke's disease has been identified to be linked to mutation in the ATP7A gene. This gene codes for?

A. a protease inhibitor B. an iron transporter

C. a copper- binding P-type ATPase D. cytochrome oxidase

Recall

Answer: C. a copper-binding P-type ATPase

81. Mutation in ATP7B gene affects the copper binding P-type ATPase. This is known as Wilson's disease. Individuals that carry this mutated gene present will all of the following signs except one. Which one is the exception?

A. copper is not excreted in the bile B. accumulation of fibrillar proteins

C. deposition of copper ion in liver and other organs D. copper toxicosis

Application

Answer: B. accumulation of fibrillar proteins

82. Deficiency of 1- antiproteinase (1- antitrypsin) is associated with emphysema. In smokers, progress to emphysema becomes faster because:

A. smoking destroys the methionine of 1- antitrypsin impairing binding to protease B. smoking releases polyaromatic hydrocarbons that bind 1- antitrypsin

C. smokers carry mutant genes for the enzyme

D. oxygen facilitates conversion of enzyme to inactive form Application

Answer: A. smoking destroys the methionine of 1- antitrypsin impairing binding to protease

83. In one genetic disease, molecular studies showed that there is premature termination of the transcription process. This should result in:

A. failure to have an mRNA code B. there will be deficiency of the protein C. RNA will be non-functional

D. all of the above Application

84. In one type of cancer, the normal gene was mutated and transformed into a cancer-inducing gene or oncogene. Since the gene coded for an enhancer that binds DNA polymerase, what is the mechanism for the proliferation of cells in the cancer?

A. presence of excessive substrates B. increase synthesis of DNA

C. cellular transformatioin D. lack of DNA binding site Application

Answer: B. increase synthesis of DNA

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85. A newly-discovered genetic disease presents with premature aging of the affected individual. It was noted in initial studies that activity of the enzyme telomerase was quite low. What mechanism explains the above observation?

A. some proteins disappear with time B. replication at telomeres is absent C. DNA chains shorten with time D. all of the above

Application

IMMUNOLOGIC - 15

I. Given patient data, determine the metabolic pathways and processes involved. 86. A highly atopic individual wil have elevated levels of:

A. Ig A B. Ig G C. Ig M D. Ig E Recall Answer: D. Ig E

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 601, Table 149 - 9}

87. Patients with bronze diabetes have: A. diabetes mellitus

B. excessive storage iron in tissues C. mutations in the HFE gene D. all of the above Recall

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 594 - 595 par. 10}

88. In a 52 year old congestive heart failure patient presenting with edema, which of the following statements is TRUE:

A. The hydrostatic pressure in the arterioles and in the veins are the same B. The hydrostatic pressure in the veins is greater than that of the arterioles C. The oncotic pressure in the arterioles is greater than that of the veins D. Edema results when fluid accumulates in the extravascular tissue spaces Application

Answer: D. Edema results when fluid accumulates in the extravascular tissue spaces Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 558 par. 6}

89. After a massive incompatible blood transfusion, the patient complained of abdominal pain and "bloody urine". Which of the following biochemical processes is TRUE of this patient?

A. The "bloody urine" is due to the Hb-Hp complex

B. The urine is due to the free hemoglobin passing thru the glomerulus C. The haptoglobin is elevated in this patient

D. All of the above Application

Answer: B. The urine is due to the free hemoglobin passing thru the glomerulus Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 592 par.3}

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90. In a patient with chronic liver disease, which of the following biochemical processes is TRUE? A. albumin production is decreased

B. erythropoietin is elevated C. haptoglobins are elevated

D. nuclear factor kappa- (NFKB) is stimulated Application

Answer: A. albumin production is decreased

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 591 par. 2 - 4}

IV. Given a clinical condition, identify the genetic/immunologic processes involved 91. A pregnant woman most likely will transmit this immunoglobulin to her baby:

A. Ig G B. Ig A C. Ig M D. Ig E Recall Answer: A. Ig G

Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 601, Table 49-9}

92. A patient with emphysema may have a deficiency in: A. albumin B. 1 - antitrypsin C. 2 - macroglobulin D. ceruloplasmin Recall Answer: B. 1 - antitrypsin

93. Which organ is seriously affected in patients with multiple myeloma? A. liver B. kidneys C. intestines D. brain Recall Answer: B. kidneys

94. Patient with agammaglobulinemia is a serious immunodeficiency disease of:

A. Ig M B. Ig G C. Ig A D. Ig E Recall Answer: B. Ig G

95. Which protein is deposited in large amounts in brain tissues in patients with alzheimer's disease A. C - reactive protein B. C - peptide C. Amyloid  D. 2 macroglobulin Recall Answer: C. Amyloid 

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96. On a routine physical examination, a first year nursing student was told by the examining physician that he has golden pigment ring around his cornea of both eyes. Which of the following laboratory results yield abnormal results?

A. serum copper B. serum calcium C. urinary creatinine D. urine sodium Application

Answer: A. serum copper

97. A medical student came to the emergency room because of difficulty of breath and rashes all over her body after attending a birthday party. The resident on duty gave her a shot of hydrocortisol which provided a dramatic relief to the student. The relief is due to: A. stimulation of the JAK-STAT pathway

B. inhibition of NF-KB

C. regulation of nuclear receptor family D. stimulation of tyrosine kinase activity Application

Answer: B. inhibition of NF-KB

98. Patient's with Crohn's disease may die because of: A. infection

B. hypoalbuminemia

C. protein losing gastroenteropathy D. all of the above

Application

99. Which statement is TRUE of a patient with recurrent respiratory tract infections: A. Circulating immunoglobulins are decreased

B. Cell-mediated immunity is decreased C. T cells are involved

D. All of the above Application

Answer: A. Circulating immunoglobulins are decreased Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 599 par. 2}

100. A kidney transplant patient developed graft rejection reactions on the 7th_{day post transplant.}

Which statement is TRUE of this patient: A. Plasma cells are the primary culprint B. This is hormonal response

C. This is T cell-mediated immunologic response D. Bone marrow transplant is a must for this patient Application

Answer: C. This is T cell-mediated immunologic response Reference: Harper's Illustrated Biochemistry 27th_{ed., p. 599 par. 2}

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