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Biochemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. What are the characteristics of prader willi syndrome How does it occur
Carbomoyl phosphate synthetase I
Targets the proteins for lysosome
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

2. What substance inside the cells replenishes NADPH
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
G6PD
Methionine encode by only 1 codon (AUG)
Phenylalanine

3. What is the activated carrier for phosphoryl
ATP
Must be both activated and inactivated for cell cycle to progress
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Actin and myosin

4. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Transfers methyl units
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Skin

5. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Palate - facial and cardiac defects
Infection - free radicals generated by inflammatory response
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Inc dicarboxylic acids - dec in glucose and ketones

6. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Fibroblast
Proton gradient
Fibrofatty replacement of muscle - cardiac myopathy
Collagen

7. How is ATP used by the cell
ATP hyrdolysis couple to energetically unfavorable rxns
B48 - AIV - CII - E
Karyotyping
RNA

8. How many ATP are produced by anearobic glycolysis per molecule of glucose
APRT + PRPP
Two
Acetyl - CoA
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis

9. What does the golgi do to sugars in proteoglycans and of selected tyrosine on proteins
Paclitaxel
AR
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Sulfation

10. in a 100 meter sprint Where does energy come from
Hypoglycemia
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Stored ATP - creatine phosphate - anaerobic glycolysis
CGG

11. How many ATP are created by aerobic metobolism of glucose in muslce via what shuttle
Cleft palate - cardiac abnl - pregs test
Glycine - aspartate - glutamine
30 - glycerol -3- phosphate shuttle
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

12. What is NADPH used for
Wernicke - korsakoff - dry and wet beriberi
Anabolic processes as a supply of reducing equivalents
B100
Robertsonian translocation and mosaicism

13. What is the activated carrier for methyl groups
Von Gierke's - Pompe - Cori - McArdle
SAM
Karyotyping
In ER - glucose 6- P to glucose

14. What does helicase do
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Unwinds DNA template at replcation fork
4 under the floor
Phenytoin - MTX - and sulfonamides

15. Where is vit B12 found
Promotor - TATA box - and CAAT box - AT rich
Fasting
Dermatitis - glossitis - and diarrhea
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver

16. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Removes phosphate group from substrate
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Oligomycin
32 - malate aspartate shuttle

17. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Males are infertile due to bilateral absence of vas deferens
Cre - lox system
Oxidative and nonoxidative - no ATP produced or used
Muscle

18. What inhibits pyruvate kinase
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
ATP and alanine
Proton gradient
II - VII - IX - X (1972) protein C and S

19. Type I bone
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Glucose 6 phosphatase
BOne

20. What residues are hydroxylated in step 2 of collagen synthesis - and What does this require
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Cri du chat
Result from phagocytic removal of heinz bodies my macs - G6PD def
Proline and lysine - vit C

21. What enzyme converts glucose 1 p to UDP glucose
Transmitted only through mother - all offspring of affected females may show signs of disease
Antioxidant - protects RBCs and membrances from free radical damage
UDP glucose pyrophosphorylase
Base + ribose

22. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Heterochromatin = HighlyCondensed
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Mucus secreting globlet cells and antibody secreting plasma cells

23. What is the hardy weinber heterozygote prevalence
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
2pq
Silencers
Wobble

24. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Grows slowly - collapses quickly
Uses ATP to add high energy phophate group onto substrate
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

25. What are the findings in PKU
Cre - lox system
L form
Oxalacetate
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

26. What bone disorder has x linked dominant inheritance
CFTR gene - 7 - Phe 508
Glucose 6 phosphate dehydrogenase (G6PD)
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Fructose 1 -6 bisphosphate

27. What enzyme adds Cl - to the H202 to makes bleach
LDL
Changed AA (convservative - new AA is similar in chemical structure)
GAA
Myeloperoxidase

28. In which direction is protein synthesized
Intermediate filaments
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
After day 1
N to C

29. How do tetracyclines work
Schilling test
1 -25 OH2 D3 = calcitriol
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Facial flushing

30. What are the names and sources of the two types of vit D found in nature
Degradation of TG stored in adipocytes
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Protective against malaria
Schilling test

31. What do the single stranded binding proteins do
Prevent strands from reannealing
Neurons
Isocitrate dehydrogenase
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms

32. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
HDL
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
NADH - NADPH - FADH2
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

33. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Cartilage - hyaline - vitreous body - nucleus pulposus
Oxidative and nonoxidative - no ATP produced or used
Tuberous sclerosis
Nissl body - enzyme and NTs

34. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
OTC has hyperammonemia - orotic aciduira does not
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Connective tissue
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

35. Where is EtOH dehydrogenase located
Cytosol
Uses ATP to add high energy phophate group onto substrate
Sucrose = glucose + fructose - lactose = glucose + galactose
Colchicine

36. What happens with dry beriberi
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Polyneuritis - symmetrical muscle wasting
Hereditary spherocytosis
Actin and myosin

37. What does lipoprotein lipase do
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Krabbes - galactocerebrosidase - galactocerebroside - AR
Adds 2 carbon with the help of biotin
Degredation of TG circulating in chylomicrons and VLDLs

38. What is the Name and fxn of vit B12
Nissl body - enzyme and NTs
Rb and p53
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
HMG- CoA reductase

39. what disease can cause pellagra
Dermatitis - enteritis - alopecia - adrenal insuff
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Degredation of dietary TG in small intestine
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

40. What are pyrimidines made from
N to C
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Adenosine to inosine
Orotate precursor - with PRPP added later

41. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Griseofulvin
Removes phosphate group from substrate
Lactate
Four

42. cytoskeletal elements in micorvilli - muscle contracting fibers - cytokenesis - adherens jxns
1 kind with multiple subunits
Actin and myosin
Kidney - ears - eyes
Proline and glycine (non glycosylated forms)

43. What happens in vit D excess
75 to 90 - cloverleaf
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Pyruvate - NAD+ - CoA
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

44. What does the TCA cycle produce per 1 acetyl CoA
Marasmus - muscle wasting
Comlex II
TTP
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

45. What is the activated carrier for 1 carbon units
NF2 on chromosome 22
THFs
N to C
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx

46. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Heterochromatin = HighlyCondensed
Phosphorylation - glycosylation - hydroxylation
75 to 90 - cloverleaf
Acetyl - CoA

47. How does warfarin work
Inc dicarboxylic acids - dec in glucose and ketones
Vit K antagonist
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Binds to LDL receptor - mediates VLDL secretion

48. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Heterochromatin = HighlyCondensed
Transfers methyl units
Sucrose = glucose + fructose - lactose = glucose + galactose
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

49. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Alkaptonuria - may have debiliating arthralgias
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Arg - lys - his - arg is most basic - has has no charge at body pH

50. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Tuberous sclerosis
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
VLDL