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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 activated carrier for methyl groups
Carbomoyl phosphate synthetase II
TTP
Phosphorylation - glycosylation - hydroxylation
SAM

2. What enzyme esterifies 2/3 of plasma cholesterol
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Hypoxanthine to xanthing and xanthine to uric acid
LCAT (lecithin cholesterol acyltransferase)
Glycine - aspartate - glutamine

3. How do aminoglycosides work
By inhibiting formation of the initiation complex and cause misreading of mRNA
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
HVA
Anchor muscle fibers - primarily in skeletal and cardiac muscle

4. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Von hippel lindau - 3
Inc glucagon - inc cAMP - inc PKA
Disease
DTMP

5. Describe robertsonian translocation
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

6. Name 5 drugs that interfere with nucleotide synthesis
Mediates chylomicron secretion
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

7. What kind of RNA is transported out of the nucleus
Arginine
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Only processed RNA

8. What initiates protein synthesis
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
ADPKD
Microtubules
MRNA

9. What does hepatic TG lipase do
Degradation of TG remaining in IDL
Carbomoyl phosphate synthetase I
Thymic - parathyroid and cardiac
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

10. What substances induce phosphofructokinase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
AMP - fructose 2 -6 BP
Hypoxanthine to xanthing and xanthine to uric acid
Niacin - constituent of NAD and NADP - derived from tryptophan

11. What is the result of vit B5 def
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Transmitted only through mother - all offspring of affected females may show signs of disease
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
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

12. What does biotin def cause
Chylomicrons
17 - 17 letters in von Recklinghausen
Dermatitis - alopecia - enteritis
Von Gierke's - Pompe - Cori - McArdle

13. Type I collagen
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Lysine and leucine
Q -
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

14. What metabolic rxns occur in both the cytoplasm and mitochondria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Fibrofatty replacement of muscle - cardiac myopathy
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Uses ATP to add high energy phophate group onto substrate

15. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
AMP - fructose 2 -6 BP
Tropoelastin with fibrillin scafolding
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Hyperlipidemia

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

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17. What does helicase do
N to C
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
F16BP
Unwinds DNA template at replcation fork

18. What happens in a B12 def
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Avidin
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Fed

19. How many ATP are created by aerobic metobolism of glucose in muslce via what shuttle
Inc insulin - dec cAMP - dec PKA
30 - glycerol -3- phosphate shuttle
Specific glycosylases - AP endonuclease
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

20. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Williams syndrome
Inc insulin - dec cAMP - dec PKA
Malabsorption and steatorrhea (ADEK)
APC on chromosome 5

21. trinucleotide repeat fo myotonic dystrophy
CTG
Mcardle's - skeletal muscle glycogen posphorylase
Marfans
Griseofulvin

22. Why is G6PD def more common among patients of african decent
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Protective against malaria
2 -4 DNP - aspirin
Locus heterogeneity - ocular albinism is x- linked recessive

23. What is the results of vit B1 def
Two
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Defect in fibrillin
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

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

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25. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
No
HGPRT - defective purine salvage - excess uric acid production
Debranching enzyme
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

26. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
Mutated dystrophin gene - less severe - adolescence
Intermediate filaments
Blood - bone marrown - amniotic fluid - placental tissue
Disorder of aromatic amino acid metabolism

27. What is the composition of urea and where do each part derive from
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
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
3' end (with CCA)

28. What are the function of vit C
Cri du chat
Acetyl - CoA to malonyl - CoA (2C to 3C)
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
Orotate precursor - with PRPP added later

29. What is the activated carrier for 1 carbon units
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
THFs
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

30. What is the longest time of RNA and shortest
LCAT (lecithin cholesterol acyltransferase)
Carnitine shuttle - acyl - coa from cyto to mito
Inhibits 50S peptidyltransferase
MRNA - tRNA

31. What are cyclins
Citrate - acetyl coa from mito to cyto
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism

32. developmental delay - gargoylism - airway obstruction - corneal clouding - hepatosplenomegaly
No
Transmitted only through mother - all offspring of affected females may show signs of disease
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Carnitine shuttle - acyl - coa from cyto to mito

33. What is a silent mutation
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Same AA - often base change in 3rd position of codon (tRNA wobble)
Glucose 6 phosphate dehydrogenase (G6PD)
Citrate - acetyl coa from mito to cyto

34. What is the RDE of gluconeogenesis
Fructose 1 -6 bisphosphate
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
GTP
40 - 60 - 80

35. What is the energy source for translocation
DTMP
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
Proton gradient
GTP

36. What is the amino acid precursor for catecholamines
30 - glycerol -3- phosphate shuttle
Phenylalanine
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Stored ATP - creatine phosphate - anaerobic glycolysis

37. What tissue samples are used for karyotyping
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Keep glutathione reduced so it can detoxify free radicals and peroxides
Accelearted muscle breakdown
Blood - bone marrown - amniotic fluid - placental tissue

38. In prokaryotes - What does makes the different types of RNA
Stop codon is recognized by release factor - and completed protein is released from ribosome
1 kind with multiple subunits
HDL
Superoxide dismutase

39. in a 100 meter sprint Where does energy come from
Stored ATP - creatine phosphate - anaerobic glycolysis
5' to 3'
Rb and p53
Phenylketones in urine

40. What does primase do
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
FAP
Makes RNA primer on which DNA poly III can initiate replication
Citrate - acetyl coa from mito to cyto

41. What 3 amino acids are necessary for purine synthesis
HMG- CoA reductase
Glycine - aspartate - glutamine
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Oxidative is irreversible

42. What are the clinical features of I cell diesase
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Comlex II
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Coenzyme A - lipoamide

43. What clotting factors require vit K
Peroxide
Y shaped region along the DNA template where leading nad lagging strands are synthesized
MRNA
II - VII - IX - X (1972) protein C and S

44. What are bite cells and when do you see them
Attachment of ubiquitin to defective proteins tag them for breakdown
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Schilling test
Result from phagocytic removal of heinz bodies my macs - G6PD def

45. What is the Hardy Weinberg disease prevalence equation
P2 +2pq+ = 1
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
CGG
Nissl body - enzyme and NTs

46. What does the addition of mannose -6 phosphate do
Targets the proteins for lysosome
Pseudomonas and s aureus
FMR1 gene - methylation - associated with chromosomal breakage
Q -

47. What are the results of unbalanced translocation
Nissl body - enzyme and NTs
Thymic - parathyroid and cardiac
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Inc CPK and muscle biopsy

48. What is variable expression and What is an example
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
GTP
Alpha 1 -4 glucosidase
Nature and severity of phenotype vary from 1 individual to another - NF type 1

49. What does the primary transcript combine with to form the spliceosome
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
SnRNPs and other proteins
Acetoacetate and beta hydroxybutyrate
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

50. What is the energy source for tRNA actication (charging)
Same AA - often base change in 3rd position of codon (tRNA wobble)
Alanine
ATP
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells