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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 does the start codon code for in eukaryotes and prokaryotes
Biotin
Eu - methionine - pro - formyl - methionine
OTC has hyperammonemia - orotic aciduira does not
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

2. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Inhibits the Na/K pump by binding the K side
Inc glucagon - inc cAMP - inc PKA
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Alpha - ketoglutarate dehydrogenase complex

3. What neuroanatomical strutures are injured in wernicke - korsakoff
Same AA - often base change in 3rd position of codon (tRNA wobble)
Medial dorsal nucleus of thalamus - mamillary bodies
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Oxidizes substrate

4. protein malnutrition resulting in skin lesions - edema and liver malfxn
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Kwashiorkor - small child with swollen belly
25OHD3
SNP

5. What is a nonsense mutation
Change resulting in early stop codon
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Orotic acid to UMP
Inc melt - dec fluidity

6. What are the irreversible enzymes of gluconeogenesis
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Cyclin dependent kinases;constitutive and inactive
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Niacin - constituent of NAD and NADP - derived from tryptophan

7. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Infection - free radicals generated by inflammatory response
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Kidney - ears - eyes
Connective tissue

8. Who typically has lactase def
African Americans and Asians
Superoxide dismutase
Arginine
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

9. What does fomepizole do
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Free ribosomes
Acetoacetate and beta hydroxybutyrate
Neg to pos

10. What substances directly inhibit electron transport chain
Rotenone - CN- - antimycin A - CO
Mebendazole/thiabendazole
Removal of N or C termal propeptides from zymogens to generate mature proteins
Makes RNA primer on which DNA poly III can initiate replication

11. How does cytosine become uracil
Specific glycosylases - AP endonuclease
Heterochromatin = HighlyCondensed
Deamination
Krabbes - galactocerebrosidase - galactocerebroside - AR

12. What substance inside the cells replenishes NADPH
Malabsorption and steatorrhea (ADEK)
G6PD
Same as sprint + OXPHOS
Achondroplasia

13. What is the amino acid precursor for catecholamines
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Phenylalanine
X- linked recessive
Ketone - methyl

14. What does acetyl - CoA become before becoming palmitate
Abnormal protein folding - degradation before reaching cell surface
Alkaptonuria - may have debiliating arthralgias
Inc insulin - dec cAMP - dec PKA
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

15. What is chediak higashi
Oxalacetate
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Superoxide dismutase
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

16. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Intermediate filaments
African Americans and Asians
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

17. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Autosomal recessive diseases
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Carbomoyl phosphate synthetase I

18. What is the breakdown product of NE
CAG
VMA
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

19. What are the findings in PKU
B12 and folate
Read from a fixed starting point as a continuous sequence of bases
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

20. Which anticancer drugs work on microtubules
Vincritsine/vinblastine
Liver - also in kidney and gut epithelium
Von Gierke's - Pompe - Cori - McArdle
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

21. What is the result of vit B5 def
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B

22. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Rb and p53
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma
Alanine
More than 1 codon may code for the same amino acid

23. What does amino acid catabolsim results in the formation of what?
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Epithelial cells
Griseofulvin
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma

24. What are Heinz bodies
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Krabbes - galactocerebrosidase - galactocerebroside - AR
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Oxidized hemoglobin precipiated within RBCs

25. NADPH are used In what 4 things
Night blindness - dry skin
Stored ATP - creatine phosphate - anaerobic glycolysis
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Enhancers

26. Which aspect of the spliceosome do patients with lupus make antibodies against
Assistance of upper extremities to stand up
SnRNPs
Abnormal protein folding - degradation before reaching cell surface
VLDL

27. What two proteins make up microtubules and how are they arranged
Alpha 1 -4 glucosidase
Mitochondria
Rotenone - CN- - antimycin A - CO
Alpha and beta tubulin - dimers have two GTP bound

28. What are the only purely ketogenic amino acids
Glycogenolysis to form glucose
RER
Lysine and leucine
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

29. Broadly - What can cause fat - soluble vitamin deficiencies
RNA
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
Result from phagocytic removal of heinz bodies my macs - G6PD def
Malapsorption syndromes like sprue or CF or mineral oil intake

30. When are glycogen reserves depleted
After day 1
B6
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
Base + ribose

31. How many rings do pyrimidines have
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
1 ring
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Fasting

32. Where is vit B12 found
Unmethylated - newly synthesized - HNPCC
Cri du chat
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Degradation of TG stored in adipocytes

33. What are the clinical features of I cell diesase
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Kidney - ears - eyes
HMG- CoA synthase
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

34. Where do you find elastin and What does it do
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Alcohol version of glucose - can trap glucose in cell - aldose reductase
APC on chromosome 5

35. What reaction does adenosine deaminase normally catalyze
Neuralgia
Disorder of aromatic amino acid metabolism
Adenosine to inosine
Modifies N- oligosaccharides

36. Where are FADH2 electrons transferred to...
Comlex II
5' of the incoming nucleotide
Epithelial cells
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B

37. What apolipoproteins are on chylomicrons
B48 - AIV - CII - E
Fed
Oxidative is irreversible
Epithelial cells

38. What is the trinucleotide repeat in fragile X
CGG
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Unmethylated - newly synthesized - HNPCC

39. What is variable expression and What is an example
After citruline
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

40. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Liver - also in kidney and gut epithelium
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
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

41. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
Degredation of TG circulating in chylomicrons and VLDLs
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Liver and leafy veggies
Von hippel lindau - 3

42. What are the water soluble vitamins - which ones are stored
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Chylomicrons
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
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

43. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Oxalacetate
Cofactor for LPL
B-100 - CII and E
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

44. In which structures do you find microtubules
HGPRT - defective purine salvage - excess uric acid production
2 -4 DNP - aspirin
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Flagella - cilia - mitotic spindles

45. What enzyme converts adenine to AMP
APRT + PRPP
Defect in fibrillin
Nine
Same as sprint + OXPHOS

46. What is the TX for hyper ammonemia
Protective against malaria
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Inhibits 50S peptidyltransferase
Attachment of ubiquitin to defective proteins tag them for breakdown

47. What does the addition of mannose -6 phosphate do
Modifies N- oligosaccharides
Sulfation
Targets the proteins for lysosome
Epithelial cells

48. FAP is due to deletion On what gene On what chromosome
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
APC on chromosome 5
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two

49. When does aspartate enter the urea cycle
Phenylalanine
Adenosine to inosine
After citruline
Oxidized hemoglobin precipiated within RBCs

50. Which anti breast cancer drugs work on micortubules
Paclitaxel
UGA - UAA and UAG
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
ATP and alanine