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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. 90% of ADPKD cases are due to a mutation In what gene
APKD1 on chromosome 16
SnRNPs and other proteins
Neuralgia
Orotate precursor - with PRPP added later

2. What is the Name and fxn of vit B5
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
No - its non homologous
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra

3. What feedback inhibits hexokinase
Glycogen synthase
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Karyotyping
Glucose -6 phosphate

4. Type II cartilage
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
CarTWOlage
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

5. How do glucagon/epi lead to glycogenolysis
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Must be both activated and inactivated for cell cycle to progress
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
CGG

6. Is there any requirement for homology in NHEJ
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
No - its non homologous
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
Y shaped region along the DNA template where leading nad lagging strands are synthesized

7. What is the RDE of fatty acid synthesis
Degredation of dietary TG in small intestine
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Acetyl - CoA carboxylase (ACC)
Acetyl - CoA to malonyl - CoA (2C to 3C)

8. What does an umabiguous genetic code refer to...
Each codon specifies only 1 amino acid
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Flagella - cilia - mitotic spindles
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

9. What is maternal PKU
Mitochondria
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Phenytoin - MTX - and sulfonamides
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

10. What does apoA 1 do
Dermatitis - enteritis - alopecia - adrenal insuff
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
By inhibiting formation of the initiation complex and cause misreading of mRNA
Activates LCAT

11. What are possilbe presentation for galactokinase def
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Failure to track objects or develop a social smile
1 ring
UDP glucose pyrophosphorylase

12. What happens in carnitine def
NADH - NADPH - FADH2
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

13. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
Modifies N- oligosaccharides
2 -4 DNP - aspirin
DTMP
Achondroplasia

14. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Von hippel lindau - 3
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
X linked frame shif mutation
Pseudomonas and s aureus

15. What enzyme converts adenine to AMP
APRT + PRPP
Inc Cl - in sweat
Carbomoyl phosphate synthetase I
Phenylalanine

16. In prokaryotes - What does makes the different types of RNA
Orotic acid to UMP
Fibrofatty replacement of muscle - cardiac myopathy
1 kind with multiple subunits
SAM

17. What kind of RNA is transported out of the nucleus
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
NAD+
Only processed RNA

18. What is NAD+ generally used for
Catabolic processes to carry reducing equivalents away as NADH
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Core proteins
Acetyl - CoA carboxylase (ACC)

19. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Huntingtons
Von gierkes - glucose 6 phosphatase

20. What does a phosphorylase do
Adds an inorganic phosphate onto substrate without using ATP
Adds 2 carbon with the help of biotin
Free ribosomes
Proline and glycine (non glycosylated forms)

21. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Griseofulvin
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Mediates chylomicron secretion

22. What enzyme esterifies 2/3 of plasma cholesterol
NADPH
LCAT (lecithin cholesterol acyltransferase)
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
RNA

23. inc glycogen in muscle but can't break it down - painful muscle cramps - myglobinuria with strenuous exercise - dz and enzyme

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24. 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
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
RNA
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

25. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Oxidizes substrate

26. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
G6PD
UGA - UAA and UAG
Cri du chat
Sucrose = glucose + fructose - lactose = glucose + galactose

27. What is the physiologic role of dystrophin
Arg - lys - his - arg is most basic - has has no charge at body pH
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Chylomicrons
Acetyl - CoA to malonyl - CoA (2C to 3C)

28. What are the 3 AR forms of homocystinuria
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Facial flushing
Site of steroid synthesis and detoxification of drugs and poisons
Prevent strands from reannealing

29. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
The triphosphate bond
Inc insulin - dec cAMP - dec PKA
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

30. What is mosaicism and give an example
Carbomoyl phosphate synthetase II
Superoxide dismutase
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
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

31. What happens in termination of proteins synthesis
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
3' end (with CCA)
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Stop codon is recognized by release factor - and completed protein is released from ribosome

32. What liberates glucose from glucose 6 P
Dopa decarboxylase
Glucose 6 phosphatase
Assistance of upper extremities to stand up
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

33. Acetyl - CoA carboxylase catalyzes what rxn
Acetyl - CoA to malonyl - CoA (2C to 3C)
Same as sprint + OXPHOS
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Degradation of TG stored in adipocytes

34. Why is albinism inheritnace varialbe due to...
Acetoacetate and beta hydroxybutyrate
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Locus heterogeneity - ocular albinism is x- linked recessive

35. What is kartageners syndrome
Phenylethamolamine N methyl transferase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Vit K antagonist
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra

36. bilateral acoustic schwannomas - juvenile cataracts
CGG
NF2 on chromosome 22
Proline and glycine (non glycosylated forms)
AR

37. What produces NADPH
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
HMP shunt
Inhibits RNA polymerase II - found in death cap mushrooms
Thymic - parathyroid and cardiac

38. What is the amino acid precursor for histamine
Each codon specifies only 1 amino acid
Result from phagocytic removal of heinz bodies my macs - G6PD def
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Histidine

39. What happens at the smooth ER
Liver - ovaries - seminal vesicles
Site of steroid synthesis and detoxification of drugs and poisons
Attachment of ubiquitin to defective proteins tag them for breakdown
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

40. What is the most abundant type of RNA
Avidin
Hereditary spherocytosis
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
RRNA

41. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
Abnormal protein folding - degradation before reaching cell surface
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Degredation of dietary TG in small intestine
TRNA

42. What fxn does glucokinase serve in the liver
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Von gierkes - glucose 6 phosphatase
Facial flushing
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer

43. What tissue samples are used for karyotyping
Blood - bone marrown - amniotic fluid - placental tissue
Glucose - 2Pi - 2ADP - 2NAD+
Lysine and arginine
SAM

44. characterize mitochondrial inheritance
Liver - also in kidney and gut epithelium
Transmitted only through mother - all offspring of affected females may show signs of disease
UGA - UAA and UAG
Cytosol - F 1 -6 BP to fructose 6 Phosphate

45. What is the RDE of glycogenolysis
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Dec methionine - inc cystiene - inc B12/folate
Glycogen phosphorylase
MRNA - tRNA

46. What two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine synthesis
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
Liver and leafy veggies
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

47. A small proportion of Down syndrome is due to What two genetic events
VMA
Robertsonian translocation and mosaicism
Inhibits the Na/K pump by binding the K side
Disease

48. Type IV collagen
One
In ER - glucose 6- P to glucose
Protein
Basement membrane or basal lamina

49. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
HMP shunt
HVA
PCR - denaturation - annealing - elongation
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

50. Gene imprinting implies that How many alleles are active at a single locus
Wernicke - korsakoff - dry and wet beriberi
LCAT (lecithin cholesterol acyltransferase)
One
Inhibit DNA gyrase specific for prokaryotic topoisomerase