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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 causes Hartnup's disease
Phenylketones in urine
ATP and methionine
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells

2. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Binds to LDL receptor - mediates VLDL secretion
IDL
Alpha1 antitrypsin
Autosomal recessive diseases

3. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
Von hippel lindau - 3
Tyrosine
RER
Superoxide dismutase

4. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Ribose 5- P to PRPP
Unmethylated - newly synthesized - HNPCC

5. What is the RDE of the urea cycle
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
9+2 arrangement of microtubules
Inhibits RNA polymerase II - found in death cap mushrooms
Carbomoyl phosphate synthetase I

6. What does helicase do
Must be both activated and inactivated for cell cycle to progress
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Marasmus - muscle wasting
Unwinds DNA template at replcation fork

7. What does biotin def cause
Nine
Proton gradient
Dermatitis - alopecia - enteritis
HMP shunt

8. What does the addition of mannose -6 phosphate do
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Targets the proteins for lysosome
Fibroblast
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

9. What are the findings in orotic aciduria
P+q = 1
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
Pyruvate - NAD+ - CoA
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

10. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Vit K antagonist
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
Degradation of TG remaining in IDL
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

11. What are the symptoms of vit A excess
B12 and folate
Skin
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
HMG- CoA reductase

12. What is the TX for CF and What does it do
CAG
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Palate - facial and cardiac defects

13. What is the function of Zinc
Glycolysis and aerobic respiration
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

14. bilateral acoustic schwannomas - juvenile cataracts
Alpha and beta tubulin - dimers have two GTP bound
NF2 on chromosome 22
MEN - 2A and 2B with ret gene
Inc CPK and muscle biopsy

15. What substance accumulates in galactokinase def and What is the clinical picture
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Liver and leafy veggies
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

16. What are bite cells and when do you see them
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Pyruvate to oxaloacetate (3C to 4C)
Result from phagocytic removal of heinz bodies my macs - G6PD def
Liver hepatocytes and steroid producing cells of the adrenal cortex

17. What does CATCH 22 stand for and What causes is...
Dermatitis - alopecia - enteritis
X linked frame shif mutation
BOne
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

18. What are cyclin - CDK complexes
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Must be both activated and inactivated for cell cycle to progress

19. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
TRNA
Neimann - pick - sphingomyelinase - sphingomyelin - AR
HMG- CoA reductase

20. What is the longest time of RNA and shortest
MRNA - tRNA
Orotate precursor - with PRPP added later
Thymic - parathyroid and cardiac
Inc vit B6

21. What does vit B3 def result in
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Williams syndrome
B12 and folate
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

22. What creates the musty body odor in PKU
L form
Disorder of aromatic amino acid metabolism
Tyrosine
II - VII - IX - X (1972) protein C and S

23. What are the findings in Lesch - Nyhan
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Flagella - cilia - mitotic spindles
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

24. What is the TX for hyper ammonemia
1 ring
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Oxidizes substrate
Marasmus - muscle wasting

25. What drugs can cause folate def
IMP precursor
Phenytoin - MTX - and sulfonamides
Glycine - aspartate - glutamine
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -

26. What is the Name and fxn of vit B5
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Muscle
Oxidizes substrate

27. characterize x linked dominant
Lacks glucose 6 phophatase
Reads usual codon but inserts wrong AA
Enhancers
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

28. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Proton gradient
Transmitted only through mother - all offspring of affected females may show signs of disease
Alpha - ketoglutarate dehydrogenase complex
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)

29. What is the defect in II A familial hypercholesterolemia
Tropoelastin with fibrillin scafolding
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
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

30. What is imprinting and give an example

31. What is loss of heterozygosity and give an example
Skin
In ER - glucose 6- P to glucose
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
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

32. What is a silent mutation
RRNA
Arg and his inc in histones Which bind negatively charged DNA
RRNA
Same AA - often base change in 3rd position of codon (tRNA wobble)

33. What is the amino acid precursor for catecholamines
Phenylalanine
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Actin and myosin
CGG

34. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Phosphorylation - glycosylation - hydroxylation
Terminal regions - tropocollagen
APKD1 on chromosome 16
After citruline

35. What is the exception to genetic redundancy
Acetly- CoA - CO2 - NADH
Methionine encode by only 1 codon (AUG)
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Glutamine PRPP amidotransferase

36. What is the active form of vit D
Makes RNA primer on which DNA poly III can initiate replication
Dermatitis - enteritis - alopecia - adrenal insuff
1 -25 OH2 D3 = calcitriol
Same as sprint + OXPHOS

37. What is the treatment for cystathionine synthase def
Antioxidant - protects RBCs and membrances from free radical damage
Cri du chat
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Dec methionine - inc cystiene - inc B12/folate

38. What does the mutation in the gene cause in protein synthesis
Dermatitis - glossitis - and diarrhea
CAG
Abnormal protein folding - degradation before reaching cell surface
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

39. What is the results of vit B1 def
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
DNA
5' of the incoming nucleotide
Inhibits RNA polymerase II - found in death cap mushrooms

40. Why is G6PD def more common among patients of african decent
Base + ribose + phosphate (3' -5') phosphodiester bond
Protective against malaria
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

41. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
NAD+
Ile - phe - thr - trp
X linked frame shif mutation
EtOH dehydrogenase and acetaldehyde dehydrogenase

42. In what direction are DNA and RNA synthesized

43. How do permanent cells grow and regenerate and What are examples of permanent cells
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Ca/calmodulin in muscle to coordinate with muscle activity
Glucose - 2Pi - 2ADP - 2NAD+
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

44. What substance inside the cells replenishes NADPH
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
G6PD
Microarrays
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

45. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Familial hypercholesterolemia - hyperlipidemia type IIA
Acetyl - CoA to malonyl - CoA (2C to 3C)
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Result from phagocytic removal of heinz bodies my macs - G6PD def

46. What is NADPH's role inside RBCs
Keep glutathione reduced so it can detoxify free radicals and peroxides
Intermediate filaments
Adenosine to inosine
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

47. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
PCR - denaturation - annealing - elongation
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Oxidative and nonoxidative - no ATP produced or used

48. What is the RDE of glycogenolysis
Glycogen phosphorylase
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Inhibits the Na/K pump by binding the K side
P2 +2pq+ = 1

49. What happens in carnitine def
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Inc insulin - dec cAMP - dec PKA
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
HGPRT - defective purine salvage - excess uric acid production

50. What two proteins make up microtubules and how are they arranged
Alpha and beta tubulin - dimers have two GTP bound
Inhibits 50S peptidyltransferase
Hyperlipidemia
They yield only acetyl - CoA equivalents