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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 uncoupling agents
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Adds 2 carbon with the help of biotin

2. What is disulfiram used for
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
X- linked recessive
Hyperlipidemia

3. What are the teratogenic effects of vit A and What test must be ordered before starting a woman on isotreitinoin for severe acne
Cleft palate - cardiac abnl - pregs test
Von Gierke's - Pompe - Cori - McArdle
High output cardiac failure - dilated cardiomyopathy - edema
Nissl body - enzyme and NTs

4. How does cytosine become uracil
HMP shunt
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Deamination

5. What happens in carnitine def
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Oxidizes substrate
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

6. What step of uric acid synthesis does xanthine oxidase catalyze
Hypoxanthine to xanthing and xanthine to uric acid
Neurons
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

7. What neuroanatomical strutures are injured in wernicke - korsakoff
9+2 arrangement of microtubules
Carnitine shuttle - acyl - coa from cyto to mito
Medial dorsal nucleus of thalamus - mamillary bodies
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels

8. In which state is PFK-2 active
Fed
Zero
CTG
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

9. What is kartageners syndrome
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Medial dorsal nucleus of thalamus - mamillary bodies
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

10. What does the start codon code for in eukaryotes and prokaryotes
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Breaks down acyl - coa to acetyl coa groups in mito
Accelearted muscle breakdown
Eu - methionine - pro - formyl - methionine

11. What does a mischarge tRNA do
Oxalacetate
Reads usual codon but inserts wrong AA
Free ribosomes
Dec DNA - dec lymphos leads to SCID

12. What is the amino acid precursor for catecholamines
Phosphofructokinase 1
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Phenylalanine
Blood - bone marrown - amniotic fluid - placental tissue

13. What causes Marfan syndrome
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Defect in fibrillin
Base + ribose + phosphate (3' -5') phosphodiester bond

14. What enzyme esterifies 2/3 of plasma cholesterol
PMNs
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
LCAT (lecithin cholesterol acyltransferase)
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

15. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
B12 and folate
CG- 3 > AT-2 - More CG content - melting point goes up
Tropoelastin with fibrillin scafolding

16. What part of the pre mRNA contains the actual genetic information coding for protein
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
CFTR gene - 7 - Phe 508
Exons

17. What is the function of Zinc
Glucose - 2Pi - 2ADP - 2NAD+
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Acetyl - CoA carboxylase (ACC)
RNA

18. ADPKD is associated with What additional conditions
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Oxidative is irreversible
Huntingtons
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele

19. central and peripheral demyelination with ataxia and dementia
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
B-100 - CII and E
High output cardiac failure - dilated cardiomyopathy - edema
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

20. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Acetyl - CoA
Krabbes - galactocerebrosidase - galactocerebroside - AR
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Marfans

21. What enzyme does fructose metabolism bypass to reach glycolysis
VMA
Kwashiorkor - small child with swollen belly
PFK - rate limiting enzyme
Dopa decarboxylase

22. What amino acid makes up most of the octamer
Lysine and arginine
AR
Euchromatin
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females

23. What is the RDE of glycogen synthesis
Neg to pos
Glycogen synthase
Liver and leafy veggies
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

24. What are the findings in orotic aciduria
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Peroxide
Zero
Change resulting in early stop codon

25. What shape does the RNA generate during splicing and why?
Lariat shape in order and remove intron precisely and join 2 exons
CTG
Cofactor for LPL
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

26. What is the most abundant type of RNA
No
Type II
RRNA
Inhibit DNA gyrase specific for prokaryotic topoisomerase

27. Why can't muscle produce in gluconeogenesis
Lacks glucose 6 phophatase
Consesus sequenec of base pairs
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
O- oligosaccharaides

28. What is the function of biotin
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Oligomycin
X linked frame shif mutation

29. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Glycogen phosphorylase
Niacin - constituent of NAD and NADP - derived from tryptophan
Particular sequence of DNA where replicatino begins - may be single of multiple
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

30. What tissues have both enzymes of sorbitol metabolism
Asp and Glu
NADPH
Liver - ovaries - seminal vesicles
FMR1 gene - methylation - associated with chromosomal breakage

31. This is the site where negative regulators bind
Procollagen - triple helix of 3 alpha collagen chains
Proline and glycine (non glycosylated forms)
25OHD3
Silencers

32. What does the passage of electrons result in that when coupled to OXPHOS drives the production of ATP
Mebendazole/thiabendazole
Proton gradient
Liver - also in kidney and gut epithelium
Creat a nick in the helix to relieave supercoils created during replication

33. What does inc phenylalanine lead to...
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Ribose 5- P to PRPP
Phenylketones in urine
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

34. What are ketone bodies made from - where are they metabolized and how are they excreted
Lariat shape in order and remove intron precisely and join 2 exons
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
HDL

35. What are the symptoms of vit A def
Night blindness - dry skin
Mediates chylomicron secretion
Carnitine shuttle - acyl - coa from cyto to mito
RER

36. What are the results of unbalanced translocation
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
4 under the floor
Base + ribose
CG- 3 > AT-2 - More CG content - melting point goes up

37. Name 5 drugs that interfere with nucleotide synthesis
MEN - 2A and 2B with ret gene
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Prevent strands from reannealing
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

38. What are pyrimidines made from
Orotate precursor - with PRPP added later
UGA - UAA and UAG
Liver - ovaries - seminal vesicles
Glycine

39. Do balanced translocations cause abnl phenotype
No
EtOH dehydrogenase and acetaldehyde dehydrogenase
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Liver hepatocytes and steroid producing cells of the adrenal cortex

40. What does the addition of mannose -6 phosphate do
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Cartilage - hyaline - vitreous body - nucleus pulposus
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Targets the proteins for lysosome

41. What is codominance and give an example
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Exons
Neither of 2 alleles is dominant - blood groups
Same as sprint + OXPHOS

42. In what cells do the respiratory burst occur
Skin
NADPH
PMNs
TRNA

43. Why enzyme breaks down elastin and what enzyme inhibits it
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females
Elastase - inhibited by alpha1 antitrypsin
CFTR gene - 7 - Phe 508
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

44. What are the complications/signs of familial hypercholesterolemia
Liver and leafy veggies
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Epithelial cells

45. caf
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
4 under the floor
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Neurofibromatosis type 1 (von Recklinghausens disease)

46. What activates the pyruvate dehydrogenase complex
Adds an inorganic phosphate onto substrate without using ATP
Exercise: inc NAD/NADH - inc ADP - inc Ca
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Degradation of TG remaining in IDL

47. Describe the replication fork
Superoxide dismutase
Males are infertile due to bilateral absence of vas deferens
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Y shaped region along the DNA template where leading nad lagging strands are synthesized

48. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
RNA
PMNs
Familial hypercholesterolemia - hyperlipidemia type IIA

49. What is the results of vit B1 def
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
NADH - NADPH - FADH2
Wrinkles and acne
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

50. What does degenerate/rundant genetic code refer to...
Tryptophan
Glucose - 2Pi - 2ADP - 2NAD+
Acetyl - CoA to malonyl - CoA (2C to 3C)
More than 1 codon may code for the same amino acid