Biochem Genetics 2007

8/8/2019 Biochem Genetics 2007

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1. A 13 yr old boy with a 5-year history of Type 1 Diabetes came in with low bloodsugar. (40 glucose) They gave him glucagon and his glucose level went up to 175.a. A. cyclaseb.G. cyclasec. intranuclear....d. seronine/theronine kinase activitye. tyrosine kinase activity

2) Clone protein made more alpha helices in 50% ETOH than in water. Why?a. competitive hydrogen bond.....

b. ....covalent...c. hydrophilic interactiond. no me recuerdoe.van der waals....

3) Cual es la diferencia mas grande entre el genoma bacteriano y el de losmamiferos? yo puse que el genoma bacteriano tiene solo una senal para codificarpara diferentes procesos, mientras que el de los mamiferos es individual. De verdadno se si esta bien.

4) Como se transporta dentro de la celula el LDL? por medio de endocitosis

5) Distheria Toxin inhibited Eukaryotic protein synthesis through ADP-ribosylationto which of the following?

NAD+

IF (initiation factor)

EF (elongation factor)

ATP/ADP

Misma pregunta #6 de shelf 2006

6) Te dan una grafica de enzimas X vs fructosa 2,6 bifosfato y tienes que decir cuales un allosteric effector.

a)camp

b) ?

c) 1,6 bifosfato

d) 2,6 bifosfato


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Disminuye el Km fructose 2,6 bifosfato es un positive effector de PFK1

Allosteric effectors show sigmoidal relationships

Activators shift the graphic towards the left

Inhibitors shift graphic towards the right

Por si acaso :

Competitive inhibitors Km increases Vmax remains the same

Noncompetitive inhibitors Decrease Vmax y Km remains the same

7) An investigator is doing research on insulin receptors. He applies asubcutaneous insulin injection. Insulin receptors are activated and repression of phosphoenolpyruvate carboxykinase synthesis occurs. What happens to the insulinreceptors? a. single polypetide, extracellular domain, transmembrane domain, intracellulardomain.b. direct use of JAK c. Tyrosine kinased. Tyrosine phosphatase

e. serine/threonine proteine kinasef. calcium/calmodulin - dependent protein kinase I

8) A polypurine sequence is discovered. Which one is the probable sequence? a. 5' ACACACACACACA 3'b. 5' AGAGAGAGAGAGA 3'c. 5' CGCGCGCGCGCGC 3'd. 5' ATATATATATATA 3'

9. A 25 y old man with carnitine deficiency experiments fatigue and muscle painafter an aerobic exercise...Q factores bioquimicos causan tales sintomas? ANS: (no se como decia la respuesta correcta pero aki les doy la respuesta segun ellibro de Lippincott 4th Edition).Carnitine deficiencies result in a decreased ability of tissues to use LCFA (long-chain fatty acids) as a metabolic fuel. Inability to use LCFA for fuel greatly impairsthat tissue's ability to synthesize glucose during a fast.


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*Remember that carnitine can be synthesized in the liver and kidney but not in theskeletal or heart muscle. 10. Que causa un point mutation q causa un "misfolding" en las proteinas asintetizar?(no se la respuesta)

11)ATP Synthase uses F1/F0 region. Which ion must cross the Inner MitochondriaMembrane in order for ATP to be produced? choices where different ions ,

H+ ions was the answer

12) Case study: 36 year old woman4 months fatigue

maculate rash in her faceurine: blood and +3 proteinkidney biopsy: lupus nephritisfound antibodies in serum against ribosomes formationwhere will the Ab concentrate more? (in which part of the cell would you findthem?)correct answer was: nucleosomeANSWER: Lupus ( systemic lupus erythromatosus). Related to antibodies againstnucleosome formation, Ab will be found there.

13) A 0.15 kb HindII fragment of DNA is Southern blotted. What can be inferredfrom the figure :

1. E.coli2. salmonella

3. P.aeruginosa4. Bacillis5. Syaphylococcus

1.2.3.4.5.

XXX

Low stringency1.2.3.4.5.

XXX

XX

High stringency


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a. P. aeruginosa has two identical copies of gene X. ( Se ven en el mismo sitio los rsites)b. Gene X of E.coli is more similar to Salmonella than to Bacillis.( no xq tienediferente restriction site).c. Gene X of E.coli is identical to Staphylococcus. No, por la misma razon q arriba.d. Gene X of Bacillis is identical to Salmonella. No, same as above

14) Woman has a high carbohydrate diet with adequate glycogen and fatty acidsynthesis. When she begins a triathlon, fatty acid synthesis stops. This is dueto an decrease in :

a. TCA cycleb. Gluconeogenesisc. Glycogenolysisd. Oxidative phosphorylationbajose. Pentose phosphate shuntANSWER: El pentose pathway baja, lo cual produce bajos niveles de NADP, q esnecesario para fatty acid synthesis.

15) Cystic Fibrous is caused by a gene misfolding. What assists in the degradationof this malformed gene?

a. CoAb. CoQc. SAMd. Ubiquitine (right answer)e. (don't remember)

ANSWER: Ubiquinone con CF es q el receptor esta misfolded and is targeted fordetuctioin by proteosomes and ubiquination.

16) c-myc is over expressed in Burkitt Lyphoma. How is it overexpressed?

a. increased translationb. increased transcriptionc. (dont remember)

ANSWER-Burkitsts Lymphoma is mainly caused by Epstar- Bau viruses.-El c myc gene( oncogene) is translocated from a region ( which hasnormal transcription) to a site in chromosome 18, which is really heavy ingene transcription ( its translocated to a very strong promoter). Thisincreases transcription.-So theres over production of T lymphocytes due to increasedtranscription.


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17) (refer to drawing) The Question asked something like Where would a change ormutation cause the most damage (options A-F)

Answer: coding exon.

19. Which of the following is a difference between enzymatic activitites of RNAand DNA? Ans- The primers

20. The kinase that activates 2,6 biphos is decreased by: Ans- cAMP

21) Te dan una secuencia de un double stranded DNA y te preguntan cual seria eltrascript de RNA que la us como modelo...

22) HeLa cells que eran transformadas con un vector viral... Te preguntan cual esel efecto que tiene el estradiol en los receptores de estrgeno.

a. Aumenta la sintesis del receptorb. Aumenta la degradacion del receptorc. Disminuye la sintesis del receptord. Disminuye la sintesis de degradacion del receptor

inton

Non coding exon

Codingexon

D


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23. An enzyme has the following kinetics constants Vmax= 20uml/min/mgenzyme,Km= 6mM,Substrate concentration = 4mM and 1.0 of the enzyme. Theinitail rate for the reaction is?a. .8b. 8.0c. 1.32d. 13.2e. 20.0 24. Un investigador esta estudiando las toxinas de Corynebacterium diphteria, queinhibe la sintesis de proteinas. La pregunta es: Describe the nature of the post-translational modification/a. ADP- rybosilationb. Ionizationc. Phosphorilation

25. A boy with PKU should include in his diet which of the following amino acid? 26. John Doe has hypertriglyceremia his mother died at 45 from a heart attack thedisease. The disease is caused bya)homozygous HMG CoA def b) heterozygous HMG CoA def c) homo lipolysis defectd)hetero lipoysis defect

27. Deficiency of pyruvate kinase on erythrocytes, result in a decrease inthe oxygen affinity of hemoglobin.

Which of the following has a direct relationship with this?

a.Decrease of 2,3 BPGb. Increase of 2,3 BPGc. Drecrease use of Oxigend. Decrease in CO2

28. Initiation of transcription is indicated by which of the following related

portions of the diagram.

29) What supplies the carbons and Nitrogens for Pyrimidine synthesis?a) aspartate and glutamineb) glycine and aspartatec) glycine and glutamine


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30) An endonuclease is taken from bacteria and placed on a double stranded DNA, theendonuclease starts cutting off pieces at specific sites. When the endonuclease is studied in the

bacteria, it is inactive. What is the function of this endonuclease?a) Protects against foreign DNA

31. Diferencias entre isoenzimasa. temperatureb. k eqc. Michaelis Constantd. Km

32. What is the coenzyme for aspirate aminotransferase?Pyridoxal phosphate

33. DECIA ALGO SOBRE LOS RECEPTORES DE TIROSINE KINASE Y CUANDO EL

HGPRT LLEGA Y SE UNE A ESOS RECEPTORES LA PREGUNTA ES CON CUAL DE LOSSIGUIENTES SE FORMA UN COMPLEJO? A. CALCIUM CHANNELSB. FIBRONECTINSC. G-PROTEIND. INTERMEMBRANAL PROTEINE. PROTEIN SOMETHING

34. UNA MUJER LLEGA A LA SALA DE EMERGENCIA PADECE DIABETES MELLITUS TYPE I INGIRIO MUCHO CHAMPAGNE TIENE UN ALIENTO CON OLOR A ACETONA.CUAL DE LAS SIGUIENTES ESPERARIAS ENCONTRAR EN SUS LIVER CELLS? A.NAD/NADHB. NADP/NADPHC. ACIDO LACTICO Y SOMETHING

35. THERE WAS A HUGE DIAGRAM: THE ANSWER IS ENHANCERS. KNOW ABOUT THEM.

36. SOMETHING ABOUT IF A PROTEIN IS SMALLER THAN WHAT ITS SUPPOSED TO BE THEN WHAT KIND OF MUTATION IS IT. I WAS BETWEEN NONSENSE AND MISSENCEBUT I PUT NONSENSE.

37. Te daban un monton de informacion innecesaria... y terminaban preguntandoteque como sabias que era un competitive inhibitor. Las respuestas eran que si subeo baja Km, sube o baja velocidad; las caracteristicas generales de las encimas. Larespuesta correcta era que el Km subia.

38. Cual es la sustancia que baja la permeadilidad de la membrana celular y subesu flexibilidad?

- las opciones tenia sphingolipids, ionic lipids, phospholipids, cholesterol. La

respuesta correcta creo que es el colesterol (que en mi examen era la opcion a) .39. A urine sample of a 9 month year old turns dark upon standing. A defect in themetabolism of which of the following aminoacids is probably the cause:

a) Lysineb) Tyrosine (correct answer)c) Prolined) Valine


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40. A mutation in the 30s subunit of a bacterial ribosome would probably interferewith which of the following:

a) tRNA uploadingb) recognition of AUG initiation codon (correct answer)c) recognition of termination codond) ribosomal translocatione) peptide formation

41.Identificar una secuencia de bases rica en purinas

Buscar la secuencia q tiene mayor cantidad 3GAGAGAGAGA 5

Purinas son las G y las A

42. a mutation of E.coli causes mutation that inhibits the 3 5exonuclease activity . Whythis does not compromise the subsistence of the species?

Unlike DNA en E. coli, el RNA lack proofreading activity. Como este lack del proofreading nocompromete el survival de la especie?

Viruses are more prone to mutations (lack RNA proofreadingrepair), these leads to changes in viralantigens that allow them to avoid immune response. Ex. The antigenic shift of influenza virus leading tothe need for route vaccinations

No pasaba a la progenie

43) Un atleta que corre 100 metros lisos utiliza energia de los musculosproveniente de: Glycogeno, proteina, glycogeno y proteina y no recuerdo la otra opcion 44) Si una mujer se va a de vacaciones a una isla en el Caribe y come grandescantidades de una fruta sin madurar. Luego la llevan al hospital porque se pusopalida y con mareos. En el hospital le dieron glucosa y se recupero rapidamente. Que sistema le fallo a esta mujer? La glycolisis, lipolisis y no recuerdo los demas

45. Saberse el mecanismo de tryacylglicerol synthesis. La pregunta era enque paso del mecanismo del citrato hacia un feedforward inhi bition y lagrasa( pero creo q era epinefrina o algo asi ) hacia un feedback inhibition.


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La pregunta tiene un diagrama de sintesis con varias letras y hay q escogerel paso q hace esto. Seria la conversion que va de acetyl CoA a malonylCoA(primer paso), positive feedback por citrato y negative por malonyl,palmitoyl, epinefrina.

46.Empezaba como q con un viejito y decia de una dieta sin carbs. y ricaen proteinas, que se usaria para formar glucosa?te decia: acetoacetyl, cholesterol, alanina(la escogida), glycerol

47) Cual de los siguientes amino acidos podria ser identificado en una cadena deamino acidos por su absorbancia a 280nm?

Answer: tryptophan,

Also should phenyalanine and Tyrosina to absorb near UV light spectrum.

48) El codon que codifica para metionina puede utilizado como codon inicial y comoparte de la cadena del mensaje esto debido a que hay dos de la siguienteestructura:

a. mRNA

b. tRNA (right answer)

c. rRNA

d. 16 s

e. 30s

49. Know the steps of collagen fibril synthesis, especially, what steps thatoccurs extracellularly. (BRS p. 30)

50. PTH induces the release of calcium for the absortion of what tissue?

a. stomachb. intestinec. kidneyd. livere. bone

51. In the liver 7-alpha hydroxylase is a major enzyme in cholesterol... What is themajor product in 7- alpha hydroxylase?


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a) Cholic Acid Sintesis de bile acids a partir de cholesterol: producto final es cholic acid. Para lasintesis bile salts a partir de cholesterol se anaden grupos hidroxilo a cholesterol,luego se reduce el doble enlace de cholesterol y se reduce el hydrocarbon chain por3C's. Finalmente se introduce el grupo carboxilico al final de la cadena. Resultado:cholic acid.Enzima 7 alfa hidroxilasa: activada por cholesterol e inhibida por cholic acid

52. The primary step in ammonia (NH3, NH4) synthesis? ( Repasar ciclo amonia)* Las primeras dos opciones terminaban en renal tubules

53. An investigator finds that malonate acts as a competitor inhibitor of succinatedehydrogenase. Based on the findings below, what maximizes the inhibition of malonate onsuccinate dehygrongenase.

Succinate Dehy.

(mM)

Km Malonate

(mM)

K i

a. 1 1 1 1 b. 1 1 10 10c. 10 10 1 1d. 1 10 10 1e. 10 10 10 10

Remember: competive inhibitors: Km is increased (less affinity). What can reverse the effect of the competitor inhibitor is by increasing [S] (but I dont want that). I would say that the answer isD, verify.

54. Besides hydrogen bonds, what stabilizes the DNA double helix?a. histones binding to chromatin

b. negative charges of phosphate groupsc. 2 to 3 phosphodiester bondsd. stacking interactions between base pairs.

55. Nene que se muerde los dedos, tiene niveles altos de uric acid en el serum y laorina. Su hermano tiene lo mismo. Que deficiencia tiene?Answer: hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Recuerda elLesh-Nyhan syndrome (x-linked).

56. Abuela de 76 anos. Solo come lechuga y arroz, no come carne hace 5 anos y susistema esta impared. Que esta ocurriendo?

57- Si hay un "proton leak" en la memb. interna de la mitocondria, Cual de las siguientes aumentara?

a)concentracion de NADH en la mitocondria

b)pH de la mitocondria

c)Protones en la matriz


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d)??? ver efecto en sintesis de ATP

....(si se trata de un uncoupler al destruir el gradiente de protones, no se sintetiza ATP y la energia se

mpierde como calor,,,Fiebre.. Estudiar bien este concepto y como se afectan las cant. de

NAD/NADH,,,Protones..y en que lugar de la mitocondria estara c/u de ellos aumentado)

58-Hombre de 45 anos 48 hrs en un viaje, se presenta con severe watery diarrea por las pasadas 12

hrs.,,,Se le detecta contagio con colera,,Cual es el mecanismo de accion de esta toxina (signal

transduction) FOSFORILACION DE CUAL ENZIMA:

a)Se activa prot G, Activa Adenyl ciclasaetc

b)Fosforilasa

c)canal de Cl en memb. Plasmatica

d)Inositol 1,4,5, Trifosfato

59) Un nio que le dan quimioterapias porque tiene Acute Myelogenous leukemia.En la noche se despierta con dolor y toma analgesicos para el dolor pero no loalivia. En la maana se despierta con dolor y orina sangre. Estos sintomas soncaracteristicos de la degradacion de que cosa?Amino acidosFatty acidspurinespyrimidinesvitamin C

60) Presentan unos resultados clinicos que muestran glucosa alta y todo lo demas bajo(ketone bodies, lipidos, etc...) cual enzima esta deficiente?

a. Glucose 6-phosphate Dehidrogenase (right answer)Glucose 6-phosphate dehydrogenase deficiency impairs ability of the cell to form

NADPH essential for the maintenance of the reduced glutathione pool.

61.

62. There is a patient with cherry red spots. Que se acumula cuando estadeficiente hexosaminidasa A?

63. In the fetus what happens when there is no activity of "alfa iduronaxil"?

64) 15 year old female, brought into emergency room. Is dehydrated (and othersymptoms). They do a test before and after and put the results in a table

( H+, HCO3, Na+, K+, PCOp, etc. and the last thing in the table is that the curveshifts to the left). Why does the curve shift to the left?

a. decrease hemoglobinb. decrease ???c. increase pHd. increase PCOp


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65) Distrofia muscular por duplicacion de exones 7 y 9, esto se da por genes alu, elmecanismo deficiente es:

a. DNA topoisomerasa Ib. DNA topoisomerasa IIc. base excisiond. nucleotide excisione. La contestacion es la que falta aki..Cuando vean esta pregunta, no esninguna de las opciones que esta aki puesta de la a-d. La contestacion es laque no esta escrita, que no recuerdo cual era. Disculpen gente.

66. Malate-aspartate shuttle provides reducing agents for: (repasar el mecanismodel shuttle)

a. Citosolic superoxide

b. Citosilic Ions

c. HMGCOa

d. mitochondria NAD

67. The combination of enzymatic activity and exchange of amino groups providethe source of NH 3 to the synthesis of amino acids by..

(Essentially know the mechanisms of scavenging for free NH 3 (enzymaticallyand by transamination) to answer this question).

a. Aminoacid and glutamate dehydrogenase Glutaminase and Transaminase

b. Glutamate dehydrogenase and Transaminase

c. Glutaminase and acid oxydase

d. glutamate synthase and glutamate dehydrogenase

e. Transaminase and glutaminase

68. A dietary insuffiency in vitamin c shows a drecreased in the :

a. tetra..


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b.conversion of norepinefrina to epinefrina

c.conversion of proline to hidroxyproline

d.production of creatine

e.supply of aldehide .

69.A 65 year old man show to the physician with a 2 day history of pain andswelling of the great big toe. Examination of it demonstrated erythematic, swellingand tenderness. Serum show increase in uric acid. After treatment with a drugprogression is notice after 6 hours. que proceso o enzima la droga inhibe?

a. formation of fibril

b.microtubule proliferation

c. parathyroid production

d.xanthine oxide

70. Vineta de porfiria

71. 71. nina neonata de 36 meses va al hospital a check.. le diagnositcanachondroplasia . Causado por una mutacion en el cromosoma 4 gen #3 quecambiaba G por A... En cuan de los siguentes pudo haber sido causada....

cis-acting,mitochondriavesiculastrans-acting

72) lengthy question asking why/ a in metabolism of a four carbon molecule, why do we have lessproduct in tca?look for similar ques in old shelfs. The answer is I think choice D the only one thattalks about CO2. Everything else doesnt make sense.

Just know the reseason why if we start with 4Atp- why we have a net gain of 2

73) Protein Kinase C requires a product from a. Adenyl Cyclaseb. Guanylanyl Cyclase

c. Phospholypase CANSWER: Phospholipasa C catalyzes the formation of two potent second messangers: diacylgyceroland IP3.1. Hormone binds to a specific receptor2. The occupied receptor causes GDP-GTP exchange on Gq3. Gq, with bound GTP, moves to PLC and activates it.4. Active PLC cleaves phospatidYlinositol 4, 5 biphosphate to IP3 and diaculglycerol.5.IP3 binds to binds to a specific receptor on the ER , releasing sequestered Ca6.Diacylglycerol and Ca activate PKC at surface of the plasma membrane7.Phosphorylation of cellular proteins by protein kinase C produces some of the cellular responses tothe hormone.


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74. La madre de un nino que le sangra mucho la rodilla y es hemofilico con el factor VIII de coagulacionausente (el tio y el abuelo del nene por parte de la madre tambien tienen un historial similar al de el)esta considerando tener otro hijo y va a consultar al medico para saber cuales son las probabilidadesde que el proximo hijo salga con la misma condicion.

Respuesta: 50% de los hijos Since a male receives his single X-chromosome from his mother, the son of a healthy female silently

carrying the deficient gene will have a 50% chance of inheriting that gene from her and with it thedisease; and if his mother is affected with haemophilia, he will have a 100% chance of being ahaemophiliac. In contrast, for a female to inherit the disease, she must receive two deficient X-chromosomes, one from her mother and the other from her father (who must therefore be ahaemophiliac himself). Hence haemophilia is far more common among males than females.

75. Esta un hombre, de buena condicion fisica (te dice el peso, estatura, etc.), parado en una fila porcuatro horas. Como esperas que esten los niveles de ADH (vasopressin), angiotensina II, yaldosterona? El ejercicio provee una tabla condiferentes posibilidades para cada valor.

Tienes que escojer la opcion que te pone con flechitas que todos los valores aumentan, tanto ADH(antidiuretic hormone), como angiotensina II, como aldosterona. ADH regulate the body's retention of water, being released when the body is dehydrated; it causes the kidneys to conserve water (but notsalt), concentrating the urine, and reducing urine volume. It also raises blood pressure by inducingmoderate vasoconstriction... por lo tanto aumenta. Angiotensin II causes vasoconstriction, increasedblood pressure, and release of aldosterone from the adrenal cortex... por lo tanto tambien sube igualque la aldosterona.

78) Explain why a point mutation in the sequence of introns causes a phenotypicmutation?

Answer: RNA spliceosome defect (lariat)yo conteste esta

79) What makes proteoglycans a better lubricant and cushioning agents thanglycoproteins?

a. Proteoglycans have more N-glycosylation than O-glycosylation

Answer b. Proteoglycans have more negative charges due to their

Sulfates.c. Proteoglycans have more O-glycosylation than N-glycosylationd. Proteoglycans have the ability to aggregate the monomers.

80) What cofactor is needed for aminotransferases?a. B1b. B6c. Niacind. Biotin 81) 6 month old boy with a ventricular septum. no other familiars have the disease. What expalins thiseffect?

a. Resesive autosomal diseaseb. De novo chromosome somatic mutationc. mithocondrial DNA mutationd. Mosaicisme. Multiple gene inheritance

82)

HOR


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MONE _____________________

Serum Glucose

Cual es la hormona que tiene este comportamiento.(grafica es de hormona en el eje de Y y glucosa en sangre en el eje de X,demuestra que mientras la glucosa sube que la hormona baja)eran como 10 hormonas no se cual era. No esta glucagon en las opciones. En el musculo y en el higado, epinefrina aumenta el rompimiento de glicogeno e inhibe la sistesis deglicogeno. Epinefrina activa glycogen phosphorylase e inactiva glycogen synthase por medio decAMP-dependent phosphorylation de las enzimas, estimulando la conversion del glicogeno hepatico aglucosa en sangre (fuel for anaerobic muscular work). Epinefrina estimula la secrecion de glucagons einhibe la secrecion de insulina, asi que epinefrina al igual que glucagon aumenta la glucose en sangrapor lo que a medida que va aumentado glucose en sangre.En musculo, Epinefrina estimula glicolisisEn higado, epinefrina aumenta gluconeogenesis

83) A three month old girl was brought to the emergency room at 11:00 a.m. cause theparents had difficulty rousing her and feeding her in the last three hours. The day before she hadvomit and diarrhea. At the physical exam the baby was unresponsive and had hepatomegaly. Theurinalysis showed cebaic acid, lipoic acid no ketone bodies were found. She had hypoglycemia.After I.V. of dextrose the baby starts to respond. What mechanism is affected?

a. Glycine oxidationb. Lypolisisc. Leucine oxidationd. Beta oxidation of fatty acids

84) What is an enhancer? ANS: DNA sequence that could be up or down a stream.

85) In a diet w/o carbohydrates, but rich in proteins, what will be used to form glucose?

ANS: Alaline

86. The presence of high concentration of insulin in a patient with Diabetes Mellitus Type I .....se debeen parte a la falta de induction of the glucokinase in which organ?

a) Brainb) heartc) liverd) Kidney

Glucokinase es la enzima que convierte glucose en glucose-6P en las celulas hepaticas. Glucokinasatiene la misma funcion que hexokinase , pero glucokinase tiene un Km mayor que hexokinase, yfunciona solo cuando la concentracion intracellular de glucose en el hepatocito es elevada como porejemplo en el periodo seguido luego de una comida rica en carbohidratos , cuando los niveles elevadosde glucose son llevados al higado a traves de la vena portal.

87. What pathway uses a mature erythrocyte(RBC) used to obtain energy is correct?a) Fatty acids to CO2 + H2Ob) Glucose to Lactatec) Glycogen to Lactated) Ketone bodies to CO2

Los eritrocitos no tienen mitocondria por lo que obtienen su energia de metabolismo anabolico.Glucosa --- Lactato--------------------------------L-lactate

Lactate dehydrogenase


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88. a healthy 40 year old male, height 5'9'' weight 176 lbs, 26 BMI, exercises for one hour. he beginsexerceise with the resting respiratory quotient RQ at 98, he finishes with RQ at .8. what is therelationship between the RQ and the glycogen and fat?Ans> increased utilization of glycogen and no change in fatresting q. refers to metabolism measurement in direct relationship to the amount of O 2 consumedand thus glucose is burned and CO2 formed. 89. a 22 year old man loses central vision of his left eye there was no sign of infection or trauma. 3

months later, he loses central vision of his right eye. his mother and older brothers lost their sight at35 and 22, respectively. what type of mutation cna cause this condition?a. tRNA genesb. Maternal rRNA genesc. mitochondrial DNAd. X chromosome from the fathere. X chromosome from the mother

Ans. C

90. infante que solo se esta alimentando de formula tiene problemas concysteina y aminoacidos dibasicos... (sorry pero se me olvido el resto ).aprendanse problemas con a. acidsLas opciones eran:His, leu, pro, tyr, ser...

91. Nino se alimenta solo de vegetales (dieta vegan). Presenta edma enextremidaes y cabello escaso... Yo puse kwashiorkor

Nephrosis, kwashiorkor, marasmus

92. Cual de los siguientes Ketoacidos provee esqueletos de carbono para amino acidos quetransportan dos nitrogenos desde otros tejidos al liver y kidneys? 93. La hidrolisis de cual fosfolipasa provee un aumento en calcio en respuesta de TRH?

94. Old woman with diabetes type 1 use IV insulin 4 times day to have HbA1C = 7.8 % controlled.Several occasions she had suffered hypoglycemic shocks, which of the following hormones advice hershe is having a hypoglycemic shock?a. glucagonb. insulinc. cortisold. prolactin

e. ?f. ?

Answer: Hypoglycemia is related with insulin IV administration side effects of type 1 diabetes to control thehyperglycemia could lead to hypoglycemic shocks. Too much insulin lowers sugar levels so much that could causecells lack of sugar uptake and leads to cell damage Cortisol is a hormone that respond during stress situations vs.glucagon respond during fasting state to normally control glucose levels in blood, also glucagon is responsible tomaintain glucose after an overnight fasting but are not related with stress situations as cortisol does.

95. PEP + ADP Pyruvate + ATPWhy this rxn only occurs in the forward direction as shown?

a. Presence of ADP inhibits reverse rxnb. Concentration of ATP is lower than the concentration of ADPc. G of the Rxn is large negative (-) valued. Km for ATP is lower than the km for PEPe. Km for PEP is lower than the km for pyruvate

Answer: B. is the only one that follows Pauli principle where increase in conc of reactives drive Rxn to productsformation. Cannot be choice C. since equilibrium means 50% conc of both reactives and products and does notcontribute to the direction of a reaction. Thus enzymes km could be affected but enzymes does not affect theequilibrium of a Rxn.equilibrium conc adp, atp. Also some other test takers mention choice. C as In glucolysis there is 3 irreversible withlarge G and negative vs other rxns have a G= 0. In gluconeogenesis this 3 steps are bypassed by a different setof enzymes.

96) 44 y/o man is shipwrecked for 6 weeks. He has normal glucose levelswhy?


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a. decreased ketone body synthesisb. gluconeogenesis (right answer)c. hepatic glycogen degradationd. increased hepatic glycogen synthesise. protein sntesis

97) Mutant PKA does not bind to cAMP. Which body response will be fucked up???

Creo q es es 1,25 hydroxycalciferol pero verifiquen otras respues porsecond Messenger

PKA es activada por cAMP and thus se fosforila glycogen phosphorylaseb, therefore si no se enlaza cAMP a PKA entonces no se va a degradarglicgeno. Epinephrine se pega al receptor y activa adenylyl cyclasepara hacer cAMP y esto se pega a PKA, PKA fosforilase phosphorylasekinase B y la activa. Phosphorylase kinase B fosforila a glycogenphosphorylase b y la activa. Glycogen phosphorylase b degrada glycogeny sube nivel de glucosa en la sangre

PTH: activadores de PKA upregulate the Vit D receptor y aumenta lainduccin de Vit D en expresin de genes de osteoblastic cells

98) Cual es la Rx de el TCA q bota CO2 y crea NADH

Answer: Ketoglutarato a succinyl Coa ces NAD and liberates CO2

99) Which of the following is the most likely for variable expression of mitochondrialdiseases in a family?

Answer: Mitocondrial DNA mutation (not sure)

100. The addition of terminal sugar to carbohydrate chain of glicosilated proteinoccurs in:

a. Endoplasmic reticulumb.Golgic.Lisosomasd. mitocondriae.membrana plasmatica

101. A 3 year old boy, with fractures of long bones, bowing and deformities of lower limbs, previous fractures and osteopenia. He have and unstable collagentype I, this is a single point mutation in gen for collagen type I. This mutation mostlikes which of the following amino acid substitution?

a. Ala-Aspb. Glu-Glnc. Gly-Glud .Tyr-Trpe. Val-Ala

104. Which intracellular signal regulates the conversion of GTP to cGMP?


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a. cAMPb.cGMPc.diacylglycerold.malonyl CoAe.NO (answer)

105. Muscle cramps, What enzyme deficiency in muscle?glycogen phosphorrylase

108. Caso: 14 yr. old boy se presenta a sala de emergencia con quemadurasen el 30% de la superficie de su cuerpo. Resultados de lab. muestran que elNitrogen excretion es mayor que el q se consume. which hormone increase isresponsible for this negative balance?

a. glucagonb. epinephrinec. growth hormoned. Thyroxine (T4)****

109. Joven de 16 a~os visita el medico en su chequeo rutinario. Todo estabien excepto que se encuentra un renal mass in his right kidney. Dan unatabla con flechas indicando el aumento o disminucion en Renin, AngiostenineII, Aldosterone.puse q las 3 aumentan- VERIFIQUEN!!!

110) A 59 y/o person have hypoalbucinemia.What molecule transport can be affected Options:CholesteroltrygliceridebilirubinAmong others..

111) tienes E.coli mRNA con sequencia de Ala cerca delterminal 3'. Donde esta la sequencia del fmet tRNA enel mRNA?

a) en el mediob) cerca del 3'c) cerca del 5'(this is the answer)d)adjacente al no se q caray

112) 6 month infant with intestine inflammation is under parenteral nutrientsupplementation. Omission of which of the following would render the synthesis of prostacyclins impossible for the infant? a) Levulinic acidb) Palmatate acidc) Eicosanoid acidd) ??


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e)??

113) Cual es el alosterico positive para fructsoa-1,6-bifosfatasaa. ATPb. AMPc. CITRATOd. no rec(Esto esta en gluconeogenesis)

114. Ketone bodies in mitochondria of brain can be degraded to CO2 & H2O but notin liver. Cual es la razon de la diferencia?

A) HMG CoA reductaseB) HMG CoA lyaseC) HMG CoA synthetase

115. When glucose is incorporated to liver glycogen which of them is considered aglycerol donor?BRS p 301,303. Lippincott 3rd ed. p 328


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116) It gives you a 5 3 DNA oligonucleotide to be transcribed to mRNA.

Answer: F

117) A 25 year old obese woman is on an extreme diet of low carbs and high fat,what components are helping to keep adequate glucose in her body? (or somethinglike this)

A. AcetoacetateB. Cholesterol


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C.GlycerolD.HydroxibutarateE. Palmitate (answer)

118: What is the immediate effect of epinephrine on its receptor?

a) recruits Ach receptorsb) opens Ca channelsc) stimulates lipolysisd) activates cAMP

119) What is the role of F26BP on PFK-1?

In response to hormonal signals - for example, the release of insulin or epinephrine -PFK2 and FBPase2 form, or hydrolyze, respectively, the compound -D-fructose 2,6-bisphosphate, a regulatory molecule controlling the activity of the enzyme

phosphofructokinase-1 or PFK1 (in mammals). PFK1, in turn, is a key regulatoryenzyme in the central metabolic pathway - glycolysis. Fructose 2,6-bisphosphatehas the effect of increasing the activity of PFK1, thus increasing the rate at whichthe principal food molecule glucose is broken down. At the same time, thisregulatory molecule also inhibits the opposing enzyme (FBPase1) in the reversepathway (gluconeogenesis) so that the synthesis of glucose is not taking place inthe same cell where glucose is being broken down (a futile cycle).

120) An obese patient with euglycymia, has an increased plasma concentration of insulin. Which of the following may be the reason for these findings?a) Deficient glycolisis enzymesb) Deficient glucagon enzymesc) Decreased dietary intake of sugarsd) Tissue resistance to insulin

122- In contrast to adult hemoglobin to fetal hemoglobin with respect tooxygen affinity?a-low affinity to 2,3-BPGb- low CO2 affinityc- low affinty to cooperative O2 bidingd- i dont remenber, but has to be with iron

123- Acetyl COa is diverted from TCA cycle to formation of fatty acids, whenwich of the following is in low concentration?a- oxaloacetateb- citratec- palminold-


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124) El tipo estaba janguiando en el desierto y tenia un hambre cabrona y no teniacomida y el anormal se comio una hoja .... que AA esensencial tiene la hoja..

Metionina es la respuesta segun Brainstorming 2006..

125. What molecule is responsible for the joining of okazaki fragments byphosphodiester linkage?

DNA Ligase

Documents

Biochem Genetics 2007