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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 is the trinucleotide repeat in fragile X
CGG
Locus heterogeneity - ocular albinism is x- linked recessive
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production

2. Which anticancer drugs work on microtubules
Vincritsine/vinblastine
Polycystic liver disease - berry aneurysm - mitral valve prolapse
1 kind with multiple subunits
Skin

3. What neuroanatomical strutures are injured in wernicke - korsakoff
5' to 3'
Acetyl - CoA
Medial dorsal nucleus of thalamus - mamillary bodies
Initiate chains

4. What is axonemal dynein
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
1 ring
Oxidative is irreversible
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

5. What apolipoproteins are on chylomicrons
B48 - AIV - CII - E
ADPKD
Adds 2 carbon with the help of biotin
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

6. What does apoB100 do
Palate - facial and cardiac defects
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Binds to LDL receptor - mediates VLDL secretion

7. NADPH are used In what 4 things
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Met - val - arg his
Supply sufficient glucose to brain and RBCs and to preserve protein

8. What is the energy source for translocation
Methionine encode by only 1 codon (AUG)
Schwann cells - lens - retina - kidneys
GTP
32 - malate aspartate shuttle

9. Why is albinism inheritnace varialbe due to...
Locus heterogeneity - ocular albinism is x- linked recessive
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Unmethylated - newly synthesized - HNPCC
UGA - UAA and UAG

10. What is the amino acid precursor for GABA and glutathione
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Glutamate
RRNA
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

11. What happens with wet beriberi
High output cardiac failure - dilated cardiomyopathy - edema
VMA
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

12. What is the RDE of TCA cycle
Isocitrate dehydrogenase
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Not all individuals with a mutant genotype show the mutant phenotype

13. What does vit C def cause
Carbomoyl phosphate synthetase I
Euchromatin
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Schwann cells - lens - retina - kidneys

14. What kind of branches do glycogen branches have
Alpha 1 -6 and alpha 1 -4
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
ATP and alanine
Foliage - small reserve in liver - eat green leaves

15. What does the vimentin stain for
B-100 - CII and E
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
They yield only acetyl - CoA equivalents
Connective tissue

16. What is a silent mutation
Two
Adenosine to inosine
Base + ribose + phosphate (3' -5') phosphodiester bond
Same AA - often base change in 3rd position of codon (tRNA wobble)

17. How do labile celss grow and regenerate and What are examples
Familial hypercholesterolemia - hyperlipidemia type IIA
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
DsRNA promotes degradation of target mRNA knocking down gene expression
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

18. What stretch of DNA that alters gene expression by binding of transcription factors
Avidin
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Orotic acid to UMP
Enhancers

19. Where are cytosolic and organellar proteins made
Intermediate filaments
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Free ribosomes
Peroxide

20. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Degredation of TG circulating in chylomicrons and VLDLs
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE
PMNs

21. Milder form of type I with nl blood lactate levels - dz and enzyme

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22. What defects characterize velocardiofacial syndrome
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Palate - facial and cardiac defects
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
Ca/calmodulin in muscle to coordinate with muscle activity

23. What happens in the first stage of collagen synthesis - and Where does it happen
Keep glutathione reduced so it can detoxify free radicals and peroxides
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
F16BP
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

24. What does a defective Cl channel do
Promotor - TATA box - and CAAT box - AT rich
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

25. What amino acid makes up most of the octamer
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Marfans
Night blindness - dry skin
Lysine and arginine

26. How do you diagnose CFTR
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Oral uridine administration
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
Inc Cl - in sweat

27. Which anti breast cancer drugs work on micortubules
Paclitaxel
Alkaptonuria - may have debiliating arthralgias
Neurofibromatosis type 1 (von Recklinghausens disease)
Nine

28. What is the activated carrier for aldehyddes
Lysine and leucine
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
Arginine
TTP

29. What are the physical findings of fragile x syndrome
Tryosine hydroxylase
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Mcardle's - skeletal muscle glycogen posphorylase

30. What are CDKs
Chylomicrons
Inc insulin - dec cAMP - dec PKA
Cyclin dependent kinases;constitutive and inactive
Collagen

31. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
Tryosine hydroxylase
Von hippel lindau - 3
Glycogen and FFA oxidation; glucose conserved for final sprinting
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

32. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
ATP and alanine
Fasting
Alpha - ketoglutarate dehydrogenase complex
RER

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

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34. What is the activated carrier for methyl groups
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Marasmus - muscle wasting
SAM
CAG - 4

35. What happens in termination of proteins synthesis
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Neurofibromatosis type 1 (von Recklinghausens disease)
Stop codon is recognized by release factor - and completed protein is released from ribosome

36. What are the 4 assumption of the Hardy Weinberg law
Inc dicarboxylic acids - dec in glucose and ketones
CG- 3 > AT-2 - More CG content - melting point goes up
Skin
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

37. What is the amino acid precuror for creatine - urea and nitric oxide
Site of steroid synthesis and detoxification of drugs and poisons
Arginine
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
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

38. What are the irreversible enzymes of gluconeogenesis
Arg and his inc in histones Which bind negatively charged DNA
More than 1 codon may code for the same amino acid
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Covalent cross - linking by lysyl oxidase to make collagen fibrils

39. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Tuberous sclerosis
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Oxalacetate
Dec DNA - dec lymphos leads to SCID

40. What are the names and sources of the two types of vit D found in nature
Exons
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Tryosine hydroxylase

41. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Orotic acid to UMP
Anchor muscle fibers - primarily in skeletal and cardiac muscle
32 - malate aspartate shuttle
Oxidized hemoglobin precipiated within RBCs

42. What bone disorder has x linked dominant inheritance
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Unwinds DNA template at replcation fork
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

43. What is the physiologic role of dystrophin
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Free ribosomes
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Phenylalanine

44. What form of amino acids are found in proteins
Coenzyme A - lipoamide
B6
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
L form

45. in a 100 meter sprint Where does energy come from
Stored ATP - creatine phosphate - anaerobic glycolysis
Fibrofatty replacement of muscle - cardiac myopathy
GTP
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

46. What is NAD+ generally used for
Proton gradient
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Catabolic processes to carry reducing equivalents away as NADH
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

47. What is the hardy weinber heterozygote prevalence
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
2pq
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
DNA

48. What do def in in enzymes of gluconeogenesis cause
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
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Seals.
Hypoglycemia

49. What is the treatment for cystathionine synthase def
VMA
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Dec methionine - inc cystiene - inc B12/folate
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

50. What does CATCH 22 stand for and What causes is...
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Four
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive