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Biochemistry

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Answer 50 questions in 15 minutes.
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1. What liberates glucose from glucose 6 P
Mebendazole/thiabendazole
Stop codon is recognized by release factor - and completed protein is released from ribosome
Collagen
Glucose 6 phosphatase

2. What is the activated carrier for aldehyddes
HGPRT - defective purine salvage - excess uric acid production
Orotic acid to UMP
TTP
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

3. What is the function and name of vit B6
Phenylalanine hydroxylase
Vit K antagonist
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan
Elastase - inhibited by alpha1 antitrypsin

4. What are the irreversible enzymes of gluconeogenesis
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Activates LCAT
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Alpha and beta tubulin - dimers have two GTP bound

5. What does DNA ligase do
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Transmitted only through mother - all offspring of affected females may show signs of disease
Seals.
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

6. Describe the structure of cilia
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Muscle
9+2 arrangement of microtubules
Cartilage - hyaline - vitreous body - nucleus pulposus

7. What is the hardy weinberg allele prevalence
P+q = 1
Ribose 5- P to PRPP
Alpha - ketoglutarate dehydrogenase complex
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

8. What does cytokeratin stain for
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Epithelial cells
Males are infertile due to bilateral absence of vas deferens
Mediates extra remnant take up

9. In eukaryotes - What does RNA poly II make
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Uses ATP to add high energy phophate group onto substrate
MRNA
O- oligosaccharaides

10. developmental delay - gargoylism - airway obstruction - corneal clouding - hepatosplenomegaly
17 - 17 letters in von Recklinghausen
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Makes RNA primer on which DNA poly III can initiate replication

11. What is a silent mutation
Same AA - often base change in 3rd position of codon (tRNA wobble)
Inhibits RNA polymerase II - found in death cap mushrooms
FAP
NADH - NADPH - FADH2

12. What is the rate determining enzyme (RDE) of glycolysis
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Phosphofructokinase 1
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

13. characterize mitochondrial inheritance
Exercise: inc NAD/NADH - inc ADP - inc Ca
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Transmitted only through mother - all offspring of affected females may show signs of disease
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year

14. How are the many staggered tropocollagen molecules reinforced
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year
Removal of N or C termal propeptides from zymogens to generate mature proteins
Glucose - 2Pi - 2ADP - 2NAD+
Covalent cross - linking by lysyl oxidase to make collagen fibrils

15. What is the RDE of de novo purine synthesis
Epithelial cells
Avidin
Glutamine PRPP amidotransferase
O- oligosaccharaides

16. What is the activated carrier for Acyl
HMG- CoA (HMG- CoA to mevalonate
Glycogenolysis to form glucose
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
Coenzyme A - lipoamide

17. The pyruvate dehydrogenase complex serves In what reaction: products
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan
APRT + PRPP
Acetly- CoA - CO2 - NADH
Oral uridine administration

18. What do B- complex vitamin deficiencies often result in
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
No
Acetoacetate and beta hydroxybutyrate
Dermatitis - glossitis - and diarrhea

19. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Anabolic processes as a supply of reducing equivalents
Exercise: inc NAD/NADH - inc ADP - inc Ca

20. What is the activated carrier for methyl groups
Pyruvate - NAD+ - CoA
Elastase - inhibited by alpha1 antitrypsin
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year
SAM

21. What reaction does adenosine deaminase normally catalyze
HMP shunt
Adenosine to inosine
Dermatitis - enteritis - alopecia - adrenal insuff
Cytosol

22. What does PURe As Gold and CUT The Py stand for
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Inc CPK and muscle biopsy
Purines= A - G pyrimidine = C - T (U)
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

23. What does DNA poly I do?
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Tryptophan
30 - 50 - 70
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

24. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy

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25. What apolipoproteins are on chylomicrons
Targets the proteins for lysosome
B48 - AIV - CII - E
Inc dicarboxylic acids - dec in glucose and ketones
P2 +2pq+ = 1

26. What part of the pre mRNA contains the actual genetic information coding for protein
Glycolysis and aerobic respiration
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Exons
Inhibits the Na/K pump by binding the K side

27. What is the purpose of the HMP shunt
Degredation of TG circulating in chylomicrons and VLDLs
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer

28. What can vit B3 be used to treat
Malapsorption syndromes like sprue or CF or mineral oil intake
Inhibits the Na/K pump by binding the K side
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Hyperlipidemia

29. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Initiate chains
Four
Oxidized hemoglobin precipiated within RBCs
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

30. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
Von hippel lindau - 3
Glycine - aspartate - glutamine
HVA

31. How does abetalipoproteinemia present and What is the defect
Protein
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Early in life - AR - inability to synthesize lipoproteins due to def in apoB100 and B48 - intestinal biopsy shows accumulation within enterocytes due to inability to export absorbed lipid as chylomicrons - failure to thrive - steatorrhea - acanthocyt
Diphyllobothrium latum

32. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
PCR - denaturation - annealing - elongation
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
PFK - rate limiting enzyme
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

33. What is the RDE of TCA cycle
Isocitrate dehydrogenase
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
Orotate precursor - with PRPP added later
Wrinkles and acne

34. What does the golgi apparatus do on asparagine
PMNs
Inc glucagon - inc cAMP - inc PKA
Modifies N- oligosaccharides
Abnormal protein folding - degradation before reaching cell surface

35. How do macrolides and clindamycin work
Inhibits RNA polymerase II - found in death cap mushrooms
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Binds 50S - blocking translocation
Free ribosomes

36. What is the activated carrier for 1 carbon units
Arginine
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
THFs
Citrate - acetyl coa from mito to cyto

37. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Must be both activated and inactivated for cell cycle to progress
Unmethylated - newly synthesized - HNPCC
APKD1 on chromosome 16
Achondroplasia

38. Acetyl - CoA carboxylase catalyzes what rxn
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Alpha and beta tubulin - dimers have two GTP bound
Acetyl - CoA to malonyl - CoA (2C to 3C)

39. What inhibits the carnitine shuttle
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
32 - malate aspartate shuttle
Malonyl coa
No

40. recurrent pulmonary infxns in CF are due to what organisms
Medial dorsal nucleus of thalamus - mamillary bodies
Neg to pos
Pseudomonas and s aureus
Changed AA (convservative - new AA is similar in chemical structure)

41. bilateral - massive enlargement of of kidneys due to multiple large cysts
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Nine
ADPKD
X- linked recessive

42. What does apoA 1 do
Must be both activated and inactivated for cell cycle to progress
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Activates LCAT
Malapsorption syndromes like sprue or CF or mineral oil intake

43. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Supply sufficient glucose to brain and RBCs and to preserve protein
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
OTC has hyperammonemia - orotic aciduira does not
25OHD3

44. What substances induce phosphofructokinase
AMP - fructose 2 -6 BP
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Glycogenolysis to form glucose

45. What are the clinical features of I cell diesase
Unwinds DNA template at replcation fork
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Lactate

46. 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
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Pseudomonas and s aureus
Scrutinizes - hydrolyzes the bond
Mediates chylomicron secretion

47. What do DNA topoisomerases do
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Free ribosomes
Enhancers
Creat a nick in the helix to relieave supercoils created during replication

48. Which anti breast cancer drugs work on micortubules
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Protective against malaria
Paclitaxel
By inhibiting formation of the initiation complex and cause misreading of mRNA

49. What are the function of vit C
Myeloperoxidase
Phenylethamolamine N methyl transferase
Cri du chat
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE

50. What happens in a B12 def
Removes phosphate group from substrate
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)