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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 else can phosphoylate phosphorylase kinase
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
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Ca/calmodulin in muscle to coordinate with muscle activity

2. trinucleotide repeat fo myotonic dystrophy
CTG
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Debranching enzyme

3. What does an umabiguous genetic code refer to...
Each codon specifies only 1 amino acid
40 - 60 - 80
TTP
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

4. How is ATP used by the cell
Base + ribose
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
ATP hyrdolysis couple to energetically unfavorable rxns

5. How does insulin inhibit glycogenolysis
Oral uridine administration
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Y shaped region along the DNA template where leading nad lagging strands are synthesized

6. What does desmin stain for
Muscle
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Tropoelastin with fibrillin scafolding

7. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Oxidative and nonoxidative - no ATP produced or used
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Inc vit B6
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora

8. Which are the basic amino acids
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
HVA
25OHD3
Arg - lys - his - arg is most basic - has has no charge at body pH

9. Which phase of the HMP shunt is reversible and Which is irreversible
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Oxidative is irreversible
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies

10. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
LDL
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Fibroblast

11. What is chediak higashi
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
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

12. What enzyme converts glucose 1 p to UDP glucose
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
UDP glucose pyrophosphorylase
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

13. Who typically has lactase def
CAG
African Americans and Asians
Neither of 2 alleles is dominant - blood groups
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

14. What tissues have both enzymes of sorbitol metabolism
Inc CPK and muscle biopsy
Liver - ovaries - seminal vesicles
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

15. What are ketone bodies made from - where are they metabolized and how are they excreted
Lysine and arginine
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
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
They yield only acetyl - CoA equivalents

16. What feedback inhibits hexokinase
Phosphofructokinase 1
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Neural tube
Glucose -6 phosphate

17. nucleotide repeat for fragile x
Skin
Protein
Williams syndrome
CGG

18. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Mediates chylomicron secretion
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Locus heterogeneity - ocular albinism is x- linked recessive
Covalent cross - linking by lysyl oxidase to make collagen fibrils

19. In mismatch repair - which strand is recognized and In what hereditary syndrome is this defective
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Unmethylated - newly synthesized - HNPCC
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Glycine

20. Where is pyruvate carboxylase found - What does it do - What does it require amd What activates it
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
LCAT (lecithin cholesterol acyltransferase)
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

21. Where is glucokinase found - What are the Km and Vmax - and what induces it
Lysine and arginine
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Glucose - 2Pi - 2ADP - 2NAD+
AMP - fructose 2 -6 BP

22. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
B100 and E
Assistance of upper extremities to stand up
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis

23. What is NADPH used for
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Rotenone - CN- - antimycin A - CO
Active secretion in lungs and GI - reabsorbs in skin
Anabolic processes as a supply of reducing equivalents

24. What does DNA ligase do
Seals.
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Adds an inorganic phosphate onto substrate without using ATP
Oxidative and nonoxidative - no ATP produced or used

25. What are the results of pancreatic insuff in CF
SnRNPs and other proteins
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
X linked frame shif mutation
Malabsorption and steatorrhea (ADEK)

26. What fxn does glucokinase serve in the liver
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Peroxide

27. Type I bone
Glycogen phosphorylase
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Alpha 1 -4 glucosidase
BOne

28. What enzyme turns ROS to H2O2
ATP and alanine
Failure to track objects or develop a social smile
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
Superoxide dismutase

29. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Dermatitis - alopecia - enteritis
Read from a fixed starting point as a continuous sequence of bases
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

30. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Tryptophan
Degradation of TG stored in adipocytes
Alpha - ketoglutarate dehydrogenase complex
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

31. What is mosaicism and give an example
Krabbes - galactocerebrosidase - galactocerebroside - AR
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Marasmus - muscle wasting
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

32. What two rxns in in glycolysis require ATP
P2 +2pq+ = 1
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

33. What is the Name and function of vit B2
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Transfers methyl units
Von gierkes - glucose 6 phosphatase

34. ADPKD is associated with What additional conditions
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Free ribosomes
Glycogenolysis to form glucose
Oral uridine administration

35. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Hereditary spherocytosis
CG- 3 > AT-2 - More CG content - melting point goes up

36. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

37. What does the CFTR channel do in the lungs - GI tract and skin
RNA
Niacin - constituent of NAD and NADP - derived from tryptophan
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Active secretion in lungs and GI - reabsorbs in skin

38. What is trimming
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
Inc glucagon - inc cAMP - inc PKA
Tropoelastin with fibrillin scafolding
Removal of N or C termal propeptides from zymogens to generate mature proteins

39. What happens in vit K def
Same AA - often base change in 3rd position of codon (tRNA wobble)
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Change resulting in early stop codon
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx

40. What does SAM do
Tyrosine
Transfers methyl units
Phosphorylation - glycosylation - hydroxylation
Post to neg

41. Which anti gout drugs work on microtubules
Conversion of NE to epi
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Mitochondria
Colchicine

42. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Mebendazole/thiabendazole
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

43. characterize x linked recessive
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
Mebendazole/thiabendazole
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Alpha 1 -4 glucosidase

44. What are covalent alterations
Phosphorylation - glycosylation - hydroxylation
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Malonyl coa
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

45. Which RNA poly opens DNA at promotor site
MEN - 2A and 2B with ret gene
Glycine
Covalent cross - linking by lysyl oxidase to make collagen fibrils
RNA poly II

46. What is the result of vit B5 def
Glucose 6 phosphatase
Dermatitis - enteritis - alopecia - adrenal insuff
Huntingtons
AR

47. How do microtubules grow and collapse
Neither of 2 alleles is dominant - blood groups
Grows slowly - collapses quickly
Arginine
ATP

48. What are the only purely ketogenic amino acids
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Lysine and leucine
HMG- CoA reductase
Specific glycosylases - AP endonuclease

49. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Alpha 1 -4 glucosidase
Targets the proteins for lysosome
Rb and p53

50. Which aspect of the spliceosome do patients with lupus make antibodies against
Specific glycosylases - AP endonuclease
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
SnRNPs
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent