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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. Name as many x- linked recessive disorders as you can

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2. What happens in folate def
Connective tissue
1 ring
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
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs

3. What regulates whether FBPase -2 or PFK-2 is active
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
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Protein kinase A
B6

4. Where is vit B12 found
RNA poly II
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

5. Type II collagen
Wobble
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Cartilage - hyaline - vitreous body - nucleus pulposus
1 kind with multiple subunits

6. What are the results of CF on male fertility
Ribose 5- P to PRPP
Males are infertile due to bilateral absence of vas deferens
Alpha 1 -6 and alpha 1 -4
Isocitrate dehydrogenase

7. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
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
Connective tissue

8. What is the amino acid precursor for histamine
Histidine
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Hypoxanthine to xanthing and xanthine to uric acid
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

9. What is the defect in II A familial hypercholesterolemia
HMG- CoA reductase
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
CAG - 4
CG- 3 > AT-2 - More CG content - melting point goes up

10. In which direction is protein synthesized
N to C
Histidine
No - its non homologous
Alpha1 antitrypsin

11. What is the smallest mutation a mircoarray can detect
Stop codon is recognized by release factor - and completed protein is released from ribosome
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
SNP
Robertsonian translocation and mosaicism

12. How does abetalipoproteinemia present and What is the defect
IMP precursor
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
Polyneuritis - symmetrical muscle wasting
Read from a fixed starting point as a continuous sequence of bases

13. What produces NADPH
HGPRT - defective purine salvage - excess uric acid production
Malonyl coa
TRNA
HMP shunt

14. What is the prevalence of an X- linked recessive disease in males and in females
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Unmethylated - newly synthesized - HNPCC
Q -
Kidney - ears - eyes

15. What is the fxn of vit K
Binds 50S - blocking translocation
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
GTP

16. What is the active form of vit D
NAD+
Lariat shape in order and remove intron precisely and join 2 exons
Epithelial cells
1 -25 OH2 D3 = calcitriol

17. What apolipoproteins are on chylomicrons
B48 - AIV - CII - E
Result from phagocytic removal of heinz bodies my macs - G6PD def
Biotin
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR

18. What is the RDE of the HMP shunt
Glucose 6 phosphate dehydrogenase (G6PD)
Poly A polymerase - signal is AAUAA
Protein
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

19. What is the TX for PKU
Polycystic liver disease - berry aneurysm - mitral valve prolapse
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
Mucus secreting globlet cells and antibody secreting plasma cells
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

20. What kind of branches do glycogen branches have
Histidine
Alpha 1 -6 and alpha 1 -4
Binds 50S - blocking translocation
Inc insulin - dec cAMP - dec PKA

21. What clotting factors require vit K
Cytosol
Cyclin dependent kinases;constitutive and inactive
Dec DNA - dec lymphos leads to SCID
II - VII - IX - X (1972) protein C and S

22. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
DNA
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Initiate chains
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

23. What 3 amino acids are necessary for purine synthesis
Foliage - small reserve in liver - eat green leaves
Anabolic processes as a supply of reducing equivalents
Males are infertile due to bilateral absence of vas deferens
Glycine - aspartate - glutamine

24. What substance inside the cells replenishes NADPH
Marasmus - muscle wasting
G6PD
Assistance of upper extremities to stand up
Coenzyme A - lipoamide

25. What liberates glucose from glucose 6 P
9+2 arrangement of microtubules
Glucose 6 phosphatase
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

26. What is maternal PKU
They yield only acetyl - CoA equivalents
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Colchicine

27. What causes Down syndrome
Carbomoyl phosphate synthetase II
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

28. What does the golgi add to serine and threonine residues
O- oligosaccharaides
Pyruvate - NAD+ - CoA
Neurons
Antioxidant - protects RBCs and membrances from free radical damage

29. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Creat a nick in the helix to relieave supercoils created during replication
Deamination
OTC has hyperammonemia - orotic aciduira does not
Binds 50S - blocking translocation

30. What ribosomes do prokaryotes have
ADPKD
PCR - denaturation - annealing - elongation
30 - 50 - 70
Exercise: inc NAD/NADH - inc ADP - inc Ca

31. What is the defect in cystinuria
Liver - also in kidney and gut epithelium
Acetyl - CoA to malonyl - CoA (2C to 3C)
After day 1
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

32. In which state is FBPase -2 active
Fasting
LCAT (lecithin cholesterol acyltransferase)
Basement membrane or basal lamina
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome

33. An inability to convert orotic acid to UMP would be caused by a deficiency either of which two enzymes

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34. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Site of steroid synthesis and detoxification of drugs and poisons
25OHD3
Ribose 5- P to PRPP
Fibroblast

35. Is there any requirement for homology in NHEJ
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
No - its non homologous
Breaks down acyl - coa to acetyl coa groups in mito
Lactate

36. What causes Marfan syndrome
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Defect in fibrillin

37. How does cytosine become uracil
Achondroplasia
Deamination
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

38. What does helicase do
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
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Result from phagocytic removal of heinz bodies my macs - G6PD def
Unwinds DNA template at replcation fork

39. Describe the structure of cilia
Cri du chat
Acetyl - CoA to malonyl - CoA (2C to 3C)
9+2 arrangement of microtubules
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

40. What are purines made from
NADPH
IMP precursor
NADH - NADPH - FADH2
Inhibit DNA gyrase specific for prokaryotic topoisomerase

41. What does a kinase do
Uses ATP to add high energy phophate group onto substrate
Must be both activated and inactivated for cell cycle to progress
Lactate
Promotor - TATA box - and CAAT box - AT rich

42. How do stable (quiescent) cells grow and regenerate and What are examples
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Glucose 6 phosphatase
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

43. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
CG- 3 > AT-2 - More CG content - melting point goes up
APC on chromosome 5
HMG- CoA (HMG- CoA to mevalonate
Carbomoyl phosphate synthetase I

44. What is the complication of cystinuria
Proline and glycine (non glycosylated forms)
Wrinkles and acne
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

45. What is the RDE of de novo pyrimidine synthesis
Targets the proteins for lysosome
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
Diphyllobothrium latum
Carbomoyl phosphate synthetase II

46. peripheral neuropathy of hands/feet - angiokeratomas - CV/renal disease - dz - def enzyme - acc substrate - inherit
ATP
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Result from phagocytic removal of heinz bodies my macs - G6PD def
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

47. What is the function and name of vit 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
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
Vit K antagonist
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

48. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Liver - also in kidney and gut epithelium
Rb and p53
TTP
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

49. What is loss of heterozygosity and give an example
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
HMG- CoA reductase
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Von Gierke's - Pompe - Cori - McArdle

50. What does NADPH oxidase deficiency result in and why
Proline and glycine (non glycosylated forms)
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Comlex II