DAVAO MEDICAL SCHOOL FOUNDATIONCOLLEGE OF MEDICINEDEPARTMENT OF BIOCHEMISTRY

LIPID CHEMISTRY / LIPID METABOLISM

OBJECTIVE:A. The students must be able to describe the chemical

nature and properties of the different types of lipids and relate them to their cellular functions

B. The students must understand the biosynthesis and catabolism of the commonly occurring lipid in human cells and explain the biochemical basis of diseases associated with abnormalities in lipid transport and metabolism

1. Of the following lipoproteins, which one is inversely related to the incidence of coronary atherosclerosis?

a. chylomicronb. high density lipoproteinc. intermediate lipoproteind. low density lipoproteine. very low density lipoprotein ( HARPER’s 25th ch 27 pp 268-271)

2. . In the shuttle of mitochondrial acetyl coenzyme A to the cytosol for fatty acid synthesis, in which step generates NADPH?

a. oxaloacetate + acetyl coenzyme A citrateb. oxaloacetate malatec. malate pyruvated. pyruvate oxaloacetatee. citrate - coenzyme A oxaloacetate - acetyl

coenzyme A( Harper’s ch 24 pp238-239)

3. The lipoprotein that serves to transport triacylglycerol from the liver to the different extrahepatic tissues:

a. chylomicronsb. high density lipoproteinsc. intermediate density lipoproteinsd. low density lipoproteinse. very low density lipoproteins

(Harper’s Ch 27 p 268-271)

4. . Which of the following apolipoproteins serves as inhibitor of lecithin:cholesterol acyltransferase (LCAT)?

a. apolipoprotein A-IIb. apolipoprotein A-IVc. apolipoprotein B-48d. apolipoprotein C-Ie. apolipoprotein C-II

( Harper’s ch 27 pp 270-271)

5. . In the following steps in ketone bodies metabolism, NADH is generated in:

a. acetoacetate acetoneb. acetoacetate beta hydroxybutyratec. acetoacetyl coenzyme A + acetyl coenzyme A

HMG coenzyme Ad. beta hydroxybutyrate acetoacetatee. HMG coenzyme A acetoacetate + acetyl

coenzyme A( Harper’s ch 24 p 244-245)

6. Human body synthesize cholesterol de novo from acetyl coenzyme A. Cholesterol synthesis occurs in which of the following organelles?

a. cytosolb. endoplasmic reticulumc. golgi apparatusd. mitochondriae. ribosomes

( Harper’s ch 28 p285)

7. . Among the following apolipoproteins, which one serves as lipid transfer protein?

a. apolipoprotein A-IVb. apolipoprotein B-100c. apolipoprotein C-IIId. apolipoprotein D

e. apolipoprotein E ( Harper’s ch 27 p 271)

8. Among the following conditions, which one is characterized by pathologic accumulation of galactocerebroside in the affected tissues.

a. Farber's Diseaseb. Fabry's Diseasec. Gaucher's Diseased. Krabbe's Diseasee. Metachromatic Leukodystrophy

( Harper’s ch 27 p 267t)

9. . Which of the lipoproteins has the highest triacylglycerol content?

a. chylomicrons

b. high density lipoproteinsc. intermediate density lipoproteinsd. low density lipoproteinse. very low density lipoproteins

(Harper’s Ch 27 p 268-271)

10. . Ketone bodies maybe synthesized from fatty acids by which of the following organs or cells?

a. skeletal muscleb. liverc. kidneyd. erythrocytese. brain

(Harper’s ch 24 p242)

11. Spontaneous decarboxylation of acetoacetate results in the formation of:

a. acetoneb. acetyl coenzyme Ac. 3-hydroxybutyrated. malonyl coenzyme Ae. propionate

( Harper’s ch 24 p 242-243)

12. Which of the lipoproteins has the highest total lipid content?a. chylomicronsb. high density lipoproteinsc. intermediate density lipoproteinsd. low density lipoproteins

e. very low density lipoproteins ( Harper’s p 268)

13. The major site of fatty acid synthesis:a. mammary glandb. liverc. kidneyd. braine. adipose tissue

(Harper’s ch 23 p 230-231)

14. Of the following lipoproteins, which one is elevated in Type I Hyperlipidemia?

a. chylomicronsb. high density lipoproteinsc. intermediate density lipoproteinsd. low density lipoproteinse. very low density lipoproteins

(Harper’s Ch 27 p 268-271)

15. Of the following lipids, which one is accumulated is tissues of patient with Tay-Sach’s Disease?

a. ceramide trihexosideb. galactocerebroside sulfatec. gangliosided. glucoceberosidee. sphingomyelin

(Harper’s p 267)

16. In the separation of plasma lipoprotein by electrophoresis on agarose gel, which fraction is located closest to the negative pole?

a. chylomicronsb. HDLc. LDLd. VLDLe. Triglycerides

(Harper’s Ch 27 p 268-271)

17. During uncontrolled diabetes mellitus or starvation, which of the following organs utilizes ketone bodies as much as 75% for its energy substrate?

a. Heartb. Brainc. Kidneyd. Skeletal muscles ( Harper’s ch 29

p 301)

18. In the biosynthesis of fatty acids, what is the compound that transports the acetate group out of the mitochondria into the cytoplasm

a. pyruvateb. malatec. citrated. acyl carnitinee. acyl coenzyme A (Harper’s

ch 23 p 236)

19. Activation of medium chain and short fatty acids occurs in the a. Ribosomesb. Mitochondrial matrixc. Golgi apparatusd. Endoplasmic reticulume. Cytosol (Harper’s

pp 238-239)

20. The committed step in fatty acid synthesis is the formation of

a. Acetyl coenzyme Ab. Acetyl acyl carrier proteinc. Malonyl coenzyme Ad. Malonyl acyl carrier protein ( Harper’s Ch

23 pp 230)

B. Carbohydtrate chemistry/ Carbohydrate metabolism

OBJECTIVES:a) The student must be able to describe adequately the

chemical properties of carbohydrates and relate them to their cellular function

b) The students must describe the interrelationships between the various pathways of carbohydrate metabolism and explain the biochemical basis of diseases resulting from impairment of carbohydrate metabolism

1. a D glucose and a L glucose area. Anomersb. Epimersc. Tautomersd. Enantiomers (Berg et al

BIOCHEMISTRY 5TH ED p 296)

2. This sugar derivative is produced by the reduction of the carbonyl group on a monosaccaharide a. sorbitol b. glucoronic acid c. glycoside d. gluconic acid ( Harper’s Ch 15 p 153)

3. Of the following hexoses, which is a constituent of glycolipids and glycoproteins? a. glucose b. galactose c. fructose d. xylulose ( Harper’s ch 56 p 676-677)

4. Which of the following glycosaminoglycans are found in large amount in cartilages a. Dermatan sulfate b. Keratan sulfate c. Choindroitin sulfate d. Heparan sulfate e. Hyaluronic acid ( Harper’s Ch 57 p 704)

5. The compound that is the probable causative factor in the development of cataract in patients with diabetes mellitus a. Dulcitol b. Fructose 1-phosphate c. galactose 1-phosphate d. glucose 1-phosphate e. sorbitol ( Harper’s p 228-229)

6. The glycogen storage disease resulting from the deficiency of muscle phosphorylase a. Pompe’s disease b. McArdle’s disease c. Her’s disease d. Forbe’s disease e. Andersen’s disease (Harper’s ch 20 p 206t)

7. What is the major energy source for spermatozoa in seminal fluid? a. Fructose b. galactose c. glucose d. ketone bodies e. xylulose

8. A patient is diagnosed as having von Gierke’s disease is likely to exhibit which of the following clinical manifestations a. an enlarged liver b. hyperglycemia c. hypolipidemia d. hypouricemia (Harper’s Ch 36 p 397)

9. This enzyme is common to both glycolysis and gluconeogenesisa. Glyceraldehyde 3-phosphate

dehydrogenaseb. glucose 6-phosphatasec. pyruvate kinased. pyruvate carboxylase

(Harper’s p 194/211)

10. In humans, liver glycogen stores are adequate up to how many hours without support from gluconeogenesis? a. 4 hours

b. 12 hoursc. 24 hoursd. 48 hours

(Harper’s pp214-217)

C. BIOENERGETICS and BIOLOGICAL OXIDATION

OBJECTIVES: 1. The students must understand the energy transformations known to occur in cells

1. The net ATP generated in the complete oxidation of beta-hydroxybutyrate is:

a. 12 ATPsb. 23 ATPsc. 26 ATPsd. 36 ATPse. 129 ATPs (Harper’s chapter 24)

2. The number of NADPH required in complete synthesis of one (1) mole of palmitic acid

a. 7b. 8c. 12d. 14e. 16 (Harper’s chapter 23)

3. Major source of ATP in aerobic organismsa. direct phosphorylationb. substrate level phosphorylationc. ATP adenylationd. Oxidative phosphorylation (Harper’s

ch 14 p137)

4. The primary pathway for the oxidation of glucosea. Embden Myerhoff pathwayb. Sorbitol pathwayc. Tricarboxylic acid pathwayd. Pentose phosphate pathway (Harper’s ch 17 p

173)

5. In the complete oxidation of one (1) mole of palmitic acid to CO2 and H2O, the total number of ATP generated is

a. 12b. 24c. 36d. 129e. 131 (Harper’s

Ch 23)

6. Synonymous with Kreb’s cyclea. Pentose phosphate pathwayb. Citric acid cylec. Oxidative phosphorylationd. Embden myerhoff pathway (Harper’s

ch 18 p 182f)

7. Anaerobic glycolysis produces how many moles of ATP per mole of glucose?

a. 2b. 6c. 8d. 12e. 24 (Harper’s

ch 19 p 190-191)

8. Rate limiting enzyme and the major regulatory enzyme in glycolysisa. triose phosphate isomeraseb. glyceride 3-phosphate dehydrogenasec. phosphofructokinased. aldolase (Harper’s

p 191/194)

9. Enzyme that links glycolysis and the citric acid cyclea. Pyruvate dehydrogenaseb. Isocitrate dehydrogenasec. Alpha-ketoglutarate dehydrogenased. Succinate dehydrogenase (Harper’s

ch 29 pp 298…)

10. Oxidative phosphorylation is carried out by respiratory assembly located in a. mitochondrial matrix b. inner mitochondrial membrane c. endoplasmic reticulum d. cytosol ( Harper’s pp 126/ 137….)

D. Protein and amino acid chemistry/ metabolism

OBJECTIVES:

1. The student must be able to describe the chemical structure and properties of proteins and amino acids

2. The student must be able to understand the principles of amino acid and protein metabolism so they can relate and apply such knowledge to the study of human health and diseases

1. Which of the following amino acid functional group pairs is not correct a) arginine:guanidine

b) histidine:imidazolec) phenylalanine: hydroxyphenyld) tryptophan : indolee) cysteine : sulfhydryl (Harper’s p 29)

2.Helical formation or Helix is a characteristic of what protein structure?

a. primaryb. secondaryc. tertiaryd. quaternarye. all of the above (Harper’s p 49)

3. Which of the following amino acids serve as the major mode of disposing ammonia from the brain?

a. alanineb. glutaminec. threonined. serinee. valine (Harper’s p

308/317)

4. Among the following amino acids, which one is converted to pyruvate through transamination reaction?

a. alanineb. methioninec. threonined. valine ( Harper’s

pp315-316)

5. Which of the following amino acids is convertible to pyruvate by direct deamination?

a. alanineb. cysteinec. glycined. serinee. threonine

6.The amino acid precursor of catecholamines:a. glycineb. prolinec. threonined. tryptophane. tyrosine ( Harper’s p 354)

7. Among the following amino acids, which one is purely ketogenic? a. isoleucine b. leucine c. phenylalanine d. threonine e. tryptophan ( Harper’s Chapter 4)

8. Urea is the major pathway of nitrogen excretion in humans. It is synthesized in the: a. brain

b. intestinec. kidneyd. livere. skeletal muscle ( Harper’s

pp315…)

9. Among the intermediates in urea cycle, which one provides the linkage of urea cycle and the citric acid cycle? a. Alpha ketoglutarate b. aspartate c. fumarate d. malate e. oxaloacetate (Harper’s pp319-321) 10. The following amino acid is GLYCOGENIC ONLY

a. aspartateb. isoleucinec. leucined. lysinee. tyrosine ( Harper’s Chapter

4)

11. Disorder of amino acid metabolism characterized by “Maple Syrup urine odor”:

a. Alkaptonuria

b. Isovaleic Acidemiac. Menke’s Disease

d. Phenylketonuria

12. What is the Isoelectric pH of albumin?a. 4.2b. 4.7c. 4.9d. 5.2e. 5.7

13. The main mode of linkage in primary protein structure isa. hydrogen bondsb. peptide bondsc. salt bondsd. covalent disulfide bondse. van der waals (Harper’s p 49)

14. Which of the following amino acids contain indole functional group?a. Arginineb. Histidinec. Phenylalanined. Tryptophane. Tyrosine (Harper’s p 29)

15. A biochemical technique used to separate molecules based on both size and charge

a. gel electrophoresisb. spectrophotometryc. ultracentrifugationd. paper chromatography ( Harper’s P48/53)

16. Which of the following enzymes funnel amino nitrogen from glutamate to urea? a. glutamate transaminase

a. alanine transaminaseb. amino acid oxidasec. glutamate dehydratased. glutamate dehydrogenase (Harper’s

pp319-321)

17. Amino acid precursor of serotonina. alanineb. aspartatec. tryptophand. methioninee. tyrosine

18. The metabolism of the following amino acid leads to the production of small amounts of nicotinic acid in humans

a. cysteineb. methioninec. serined. tryptophane. valine ( Harper’s chapter 42)

19. A metabolite of the following amino acid is a substrate for branched-chain keto-acid dehydrogenase

a. arginineb. lysinec. methionined. prolinee. valine ( Harper’s chapter 4)

20. Which of the following is a non essential amino acid?a. leucineb. tyrosinec. lysined. methioninee. valine ( Harper’s chapter 4)

D. Nucleic acid chemistry/metabolism/ GeneticsOBJECTIVES:

1. The student should be able to describe the structural organization of nucleosides, nucleotides and nucleic acids and relate them to their cellular functions2. The students should discuss and understand the

biochemical basis of diseases resulting from impairment in the biosynthetic and catabolic pathways of purine and pyrimidine nucleotide metabolism

1. The most abundant free nucleotide in mammalian cellsa. Adenosine diphosphateb. Cyclic AMPc. Adenosine triphosphated. Adenosine monophosphatee. Phosphoadenosine phosphosulfate

( HARPER’S 25th p. 379)

2. A purine analog which is widely used in the treatment of gout a. aspirin

b. azathioprine c. allopurinol d. 5-iododeoxyuridine e. 5-flourouracil (HARPER’S CH 35 p-382)

3. Okasaki fragments are a. short non coding DNA segments b. short DNA fragments attached to RNA primers during replication c. produced when histone biosynthesis is inhibited d. mitochondrial DNA fragments complexed with histones (HARPER’S CH 38 p- 424)

4. RNA and DNA diifer from each other , in that: a. in DNA, the nucleotides run 5’ to 3’ direction b. in RNA, the sugar is linked to the base by an N-glycosidic linkage c. In RNA, the sugar is D-ribose d. in DNA, thymine is found instead of uracil ( HARPER’S CH 37 p 406)

5. Detection of purines and pyrimidines can be done because of their strong absorption of UV light at this wavelength a. 260nm b. 650 nm c. 400nm d. 600 nm (HARPER’S p-290)

6. In genetic diseases, the primary defect resides in this organelle a. endoplasmic reticulum b. nucleus c. cytoplasm d. mitochondria ( HARPER’S CH 63 P-813)

7. A PURINE BASE a. cytosine b. guanine c. uracil d. thymine ( HARPER’s ch 37 p 402)

8. Serves as the carrier of genetic information to the site of protein synthesis a. mRNA b. tRNA c. rRNA d. snRNA (HARPER’s ch37 p 407)

9. A synthetic nucleotide analog which exhibits antiviral activity useful in the treatment of herpetic keratitis a. azathioprine b. 5-iododeoxyuridine c. cytarabine d. mercaptopurine ( HARPER’s p 383)

10. Nucleotide derivative that acts as “ secondary messenger” a. ATP b. ADP c. c-AMP d. c-GMP e. GTP ( HARPER’s CH 35 p-380)

E. ENZYMES

OBJECTIVES: 1. The students must appreciate hoe protein structures of enzymes have been specifically designed to allow the catalytic action of enzymes in metabolic reactions 2. The students must understand the role of enzymes in metabolic regulation and their importance as diagnostic aids and therapeutic tools 1. Two constants are always measured whenever an enzyme is characterized. These are:

a. K1 and Kmb. Km and Vmaxc. Q10 and Vod. Vmax and Q10e. Vo and K1 (Harper’s pp 95 ff )

2. Group of enzymes that catalyze the addition or removal of water, ammonia or carbon dioxide to double bonds:

a. hydrolasesb. isomerasesc. ligasesd. lyasese. oxidoreductases

3. Nonfunctional serum enzyme that is diagnostic of obstructive liver diseases.

A. acid phosphataseB. alanine aminotransferaseC. alkaline phosphataseD. aspartate aminotransferaseE. ceruloplasmin

4. Carbonic anhydrase requires which metal ion as cofactora. ironb. zincc. magnesiumd. coppere. sodium,

5. In the effects of substrate concentration on reaction velocity, when substrate concentration is low

a. the reaction velocity is zero orderb. the reaction velocity is first-orderc. the reaction velocity is second orderd. the reaction velocity is mixed order

6. Which of the following is the target enzyme of an anti inflammatory drug, aspirin?

a. xanthine oxidaseb. transpeptidasec. HMG CoA reductased. Cyclooxygenase

e. Monoamine oxidase

7. Effect of uncompetitive inhibitors to the Maximum velocity (Vmax) and Michaelis constant (Km)

a. Vmax - none : Km – increasesb. Vmax – decreases : Km – decreasesc. Vmax – decreases : Km - noned. Vmax – decreases : Km- increasese. Vmax – increase : Km – none

(Harper’s pp 95 ff )

8. The quantitative value of the Michaelis constant or Km, is a measure of

a. the optimum condition present in the cellb. relative affinity between the substrate and enzymec. the velocity of the biochemical reactiond. the concentration of the enzyme present

(Harper’s pp 95 ff )

9. This enzyme is valuable in the diagnosis of metastatic carcinoma of the prostate gland.

a. ceruloplasminb. alkaline phosphatasec. lactate dehydogenased. acid phosphatasee. aspartate aminotransferase

10. A group of enzymes that join two molecules along with breakdown of a pyrophosphate (P-P) bond

a. ligaseb. isomerasec. lyased. transferase

F. HORMONES/ Hormone actions OBJECTIVES:

1. The students must understand the structures, properties and the roles of hormones in the maintenance of normal body metabolism

1. Among the following hormones, which one possess anti-inflammatory effect mediated through the inhibitory effect on arachidonic acid release?

a. adrenalineb. glucagonc. glucocorticosteroidd. insuline. thyroxine

2. Of the following, which is a C-19 steroid?a. cholic acidb. cortisolc. estradiold. progesteronee. testosterone ( Harper’s 577-578)

3. . Which of the following hormones is aromatic?a. aldosteroneb. cortisolc. estradiold. progesteronee. testosterone ( Harper’s p 577)

4. In the synthesis of estradiol which of the following hormone is its immediate precursor?

a. androstenedioneb. corticosteronec. pregnenolone

d. progesteronee. testosterone ( Harper’s pp599-601)

5. Site of aldosterone secretion in the adrenal cortex:a. zona fasciculatab. zona granulosac. zona intimad. zona pellucidae. zona reticularis

6. Which of the following is a C-24 steroid?a. chenodeoxycholic acidb. cortisolc. estradiold. progesteronee. testosterone (Harper’s p 292)

7. Of the following hormones, which one is an essential requirement for triacyglycerol synthesis in the adipose tissue?

a. adrenalineb. cortisolc. glucagond. insuline. thyroxine (Harper’s p246)

8. In the adipose tissue, which of the following hormones enhances the synthesis of lipoprotein lipase?

a. cortisolb. epinephrinec. glucagonsd. insuline. progesterone ( Harper’s p 246)

9. The urinary metabolite used in the diagnosis of Adrenal Pheochromocytoma:

a. hydroxyindoleacetic acid (HIAA)b. hydroxytryptaminec. hydroxytryptophand. normetanephrinee. vanillylmandelic acid (VMA)

(Harper’s p 593)

10. . Which of the following is a C-18 steroid?f. chenodeoxycholic acidg. cortisolh. estradioli. progesteronej. testosterone ( Harper’s

p577)

E. VITAMINS AND MINERALS OBJECTIVES: 1. The students must understand clearly the nutritional aspects of vitamins and minerals and appreciate their role in the maintenance of normal body functions 2. The students must correlate the clinical disorders that will result from the deficiency and excesses of these vitamins with their metabolic roles in the body.

1. An important anti oxidant because it inhibits the formation of nitrosamines during digestiona. retinolb. ascorbic acidc. tocopherold. retinoic acide. cobalamin (Harper’s

pp640-641)

2. Deficiency of this may lead to anemia in the prematures due to red blood cell hemolysisa. Vit Ab. Vit Dc. Vit Ed. Vit Ce. Vit K (Harper’s pp

647-648)

3. A cofactor of an important enzyme of the pentose phosphate pathway, transketolasea. Thiamineb. Biotinc. Niacind. Riboflavine. Pantothenic acid (Harper’s pp 627)

4. Functions as a cofactor to a carboxylase that acts on glutamate residues of clotting factor precursor proteinsa. Vitamin Ab. Vitamin Cc. Vitamiin E

d. Vitamin Ke. Biotin ( Harper’s PP 649)

5. A polyisoprenoid compound containing a cyclohexenyl ringa. Folic acidb. Pyridoxinec. Ascorbic acidd. Retinole. Biotin ( Harper’s p 642)

6. The earliest clinical symptom of Vitamin A deficiencya. defective night visionb. xerophtalmiac. presence of Bitots spotsd. Keratomalaciae. Xerosis conjunctivae (Harper’s

p 643)

7. This vitamin is important in the regulation of calcium and phosphate metabolism

a. Vitamin Ab. Vitamin Ec. Thiamind. Folic acide. Vitamin D ( Harper’s p

645)

8. If a patient exhibits low activity of propionyl CoA carboxylase, therapeutic doses of which of the following might be beneficial?

a. carnitineb. pantothenic acidc. biotind. riboflavin

e. niacin ( Harper’s p 635)

9. Strict vegetarians are susceptible to this kind of vitamin deficiency

a. pantothenic acidb. cobalaminc. folacind. niacine. pyridoxine ( Harper’s p 635)

10. . Of the following, which is the most potent form of vitamin D? a. ergosterol b. cholecalciferol c. 7-dehydrocholesterol

d. 25-hydroxycholecalciferol e. 1,25-dihydroxycholecalciferol ( Harper’s p 647)