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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 glucogenic essential amino acids
Met - val - arg his
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Skin
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

2. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
X- linked recessive
Marfans
Krabbes - galactocerebrosidase - galactocerebroside - AR
Fed

3. What is a silent mutation
Same AA - often base change in 3rd position of codon (tRNA wobble)
FMR1 gene - methylation - associated with chromosomal breakage
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Protein

4. Where are cytosolic and organellar proteins made
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Free ribosomes
Debranching enzyme

5. 90% of ADPKD cases are due to a mutation In what gene
MRNA - tRNA
APKD1 on chromosome 16
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Seals.

6. What 3 amino acids are necessary for purine synthesis
Malonyl coa
Exercise: inc NAD/NADH - inc ADP - inc Ca
Q -
Glycine - aspartate - glutamine

7. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Degredation of TG circulating in chylomicrons and VLDLs
IDL
B-100 - CII and E
After day 1

8. Mild Hurlurs + aggressive behavior no corneal clouding
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Acetyl - CoA
Chylomicrons
RNA

9. What is the energy source for tRNA actication (charging)
Cofactor for LPL
Neg to pos
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
ATP

10. What happens in carnitine def
Williams syndrome
Alpha 1 -6 and alpha 1 -4
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

11. What does a phosphorylase do
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Protein kinase A
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Adds an inorganic phosphate onto substrate without using ATP

12. cardiomegaly - systemic findings leading to early death - dz and enzyme

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13. Type IV BM
UDP glucose pyrophosphorylase
4 under the floor
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

14. How does ouabain work
Degredation of TG circulating in chylomicrons and VLDLs
Adenosine to inosine
Unwinds DNA template at replcation fork
Inhibits the Na/K pump by binding the K side

15. What is the complication of cystinuria
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Fed
Mebendazole/thiabendazole

16. What does lactase deficiency cause
Protein
Creat a nick in the helix to relieave supercoils created during replication
RNA
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea

17. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Achondroplasia
Glycogen and FFA oxidation; glucose conserved for final sprinting
RRNA
Heterochromatin = HighlyCondensed

18. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
CAG - 4
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Deamination
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

19. What is the activated carrier for electrons
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Oxidized hemoglobin precipiated within RBCs
Myeloperoxidase
NADH - NADPH - FADH2

20. What does aminoacyl tRNA synthetase do the AA before and after it binds to tRNA - and what happens if it's the wrong the match
Terminal regions - tropocollagen
Scrutinizes - hydrolyzes the bond
Malapsorption syndromes like sprue or CF or mineral oil intake
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL

21. In what direction are DNA and RNA synthesized

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22. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Flagella - cilia - mitotic spindles
Antibiotic use or excessive ingestion of raw eggs
THFs
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

23. What are the symptoms of vit A def
Core proteins
Night blindness - dry skin
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

24. How do macrolides and clindamycin work
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Binds 50S - blocking translocation
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

25. What does a decrease in decrease in NADPH lead to and why
Cyclin dependent kinases;constitutive and inactive
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
30 - glycerol -3- phosphate shuttle
Carnitine shuttle - acyl - coa from cyto to mito

26. What is the composition of urea and where do each part derive from
Result from phagocytic removal of heinz bodies my macs - G6PD def
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

27. What does the golgi apparatus do on asparagine
LCAT (lecithin cholesterol acyltransferase)
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Modifies N- oligosaccharides

28. What are the fetal screening measures for Down
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Four
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

29. What catacholamine step is SAM required for
Oxidized hemoglobin precipiated within RBCs
Conversion of NE to epi
VMA
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

30. Is there any requirement for homology in NHEJ
Each codon specifies only 1 amino acid
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Alpha 1 -6 and alpha 1 -4
No - its non homologous

31. What rxn creates ATP
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
ATP

32. Which carbon bears the triphosphate and the energy source for bond formation

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33. In eukaryotes - What does RNA poly III make
2 rings
TRNA
Marfans
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle

34. characterize x linked dominant
PCR - denaturation - annealing - elongation
Avidin
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Peroxide

35. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Von gierkes - glucose 6 phosphatase
Reads usual codon but inserts wrong AA
Tryosine hydroxylase
Glycogen synthase

36. What does vit B3 def result in
Stop codon is recognized by release factor - and completed protein is released from ribosome
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Biotin
GAA

37. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Flank pain - hematuria - HTN - progressive renal failure
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

38. Where is PEP carboxykinase found - What does it do - and What does it require
Cartilage - hyaline - vitreous body - nucleus pulposus
HVA
APRT + PRPP
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

39. What are bite cells and when do you see them
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Result from phagocytic removal of heinz bodies my macs - G6PD def
MRNA - tRNA
ATP hyrdolysis couple to energetically unfavorable rxns

40. What defects characterize DiGeorge syndrome
Glycolysis and aerobic respiration
Oxalacetate
Glycogen and FFA oxidation; glucose conserved for final sprinting
Thymic - parathyroid and cardiac

41. For eukaryotes - Where does replication begin?
Consesus sequenec of base pairs
X linked frame shif mutation
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

42. What substances directly inhibit electron transport chain
Rotenone - CN- - antimycin A - CO
25OHD3
HMG- CoA synthase
Particular sequence of DNA where replicatino begins - may be single of multiple

43. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Huntingtons
Particular sequence of DNA where replicatino begins - may be single of multiple
Familial hypercholesterolemia - hyperlipidemia type IIA
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

44. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Cri du chat
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
X linked frame shif mutation
Dopa decarboxylase

45. What two proteins make up microtubules and how are they arranged
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Alpha and beta tubulin - dimers have two GTP bound
Binds to LDL receptor - mediates VLDL secretion

46. What does a dehydrogenase do
VLDL
Phenylalanine
Oxidizes substrate
No - its non homologous

47. What happens in the first stage of collagen synthesis - and Where does it happen
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Flank pain - hematuria - HTN - progressive renal failure
X linked frame shif mutation
Tropoelastin with fibrillin scafolding

48. What are the two possible causes of albinism
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Hypoxanthine to xanthing and xanthine to uric acid
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Carbomoyl phosphate synthetase I

49. What does a western blot use for its sample
Cartilage - hyaline - vitreous body - nucleus pulposus
Protein
Phenylalanine hydroxylase
Conversion of NE to epi

50. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
RER
CG- 3 > AT-2 - More CG content - melting point goes up
Euchromatin
Chylomicrons