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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What enzyme def can cause emphysema
Liver - ovaries - seminal vesicles
Alpha1 antitrypsin
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

2. What do neurofilaments stain for
2 -4 DNP - aspirin
Prevent strands from reannealing
Neurons
Alpha 1 -6 and alpha 1 -4

3. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
Alanine
Males are infertile due to bilateral absence of vas deferens
Krabbes - galactocerebrosidase - galactocerebroside - AR
Superoxide dismutase

4. What is the RDE of glycogenolysis
Exercise: inc NAD/NADH - inc ADP - inc Ca
APKD1 on chromosome 16
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Glycogen phosphorylase

5. RNA poly can't proofread - but What can it do
APKD1 on chromosome 16
Unwinds DNA template at replcation fork
Neg to pos
Initiate chains

6. What does apoB48 do
ATP and methionine
Mediates chylomicron secretion
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
II - VII - IX - X (1972) protein C and S

7. What is axonemal dynein
Phenylethamolamine N methyl transferase
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Same as sprint + OXPHOS
Dermatitis - enteritis - alopecia - adrenal insuff

8. Pts with albinism are at inc risk For what cancer
Skin
Same AA - often base change in 3rd position of codon (tRNA wobble)
Two
Vincritsine/vinblastine

9. What are cyclin - CDK complexes
Acetyl - CoA
Must be both activated and inactivated for cell cycle to progress
Myeloperoxidase
Adenosine to inosine

10. What is the amino acid precursor for porphyrin and heme
Flagella - cilia - mitotic spindles
IMP precursor
Glycine
Kwashiorkor - small child with swollen belly

11. What is the hardy weinberg allele prevalence
Targets the proteins for lysosome
P+q = 1
Orotate precursor - with PRPP added later
Ile - phe - thr - trp

12. How do macrolides and clindamycin work
Binds 50S - blocking translocation
Poly A polymerase - signal is AAUAA
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

13. What does apoA 1 do
Cri du chat
Superoxide dismutase
Specific glycosylases - AP endonuclease
Activates LCAT

14. What is the fxn of vit E
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
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Exercise: inc NAD/NADH - inc ADP - inc Ca
Antioxidant - protects RBCs and membrances from free radical damage

15. What enzyme degrades a small amount of glycogen in lysosomes
Alpha 1 -4 glucosidase
Alpha and beta tubulin - dimers have two GTP bound
L form
Acetly- CoA - CO2 - NADH

16. What does a western blot use for its sample
Heterochromatin = HighlyCondensed
AMP - fructose 2 -6 BP
Neuralgia
Protein

17. What are the fetal screening measures for Down
Isocitrate dehydrogenase
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Free ribosomes

18. A small proportion of Down syndrome is due to What two genetic events
ATP
Robertsonian translocation and mosaicism
Tryptophan
RRNA

19. I g fat = ? Kcal
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
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Orotate precursor - with PRPP added later
Nine

20. What is the purpose of the HMP shunt
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Coenzyme A - lipoamide
AR

21. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Inc insulin - dec cAMP - dec PKA
Oxidizes substrate
After citruline
IMP precursor

22. How do fluoroquinolones work
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

23. How do stable (quiescent) cells grow and regenerate and What are examples
Neither of 2 alleles is dominant - blood groups
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Binds 50S - blocking translocation
Prevent strands from reannealing

24. What is the breakdown product of NE
VMA
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Degredation of dietary TG in small intestine

25. What is the RDE of ketogenesis
Same AA - often base change in 3rd position of codon (tRNA wobble)
Muscle
HMG- CoA synthase
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

26. What are the findings in PKU
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
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
IMP precursor

27. What is the RER called in neurons and What is made there
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Degredation of dietary TG in small intestine
Nissl body - enzyme and NTs
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

28. What is the rate limiting enzyme in cholesterol synthesis
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
HMG- CoA (HMG- CoA to mevalonate
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Intermediate filaments

29. What converts DOPA to dopamine
Dopa decarboxylase
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
Malapsorption syndromes like sprue or CF or mineral oil intake
Lacks glucose 6 phophatase

30. What causes Edwards syndrome and What is it
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
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
Peroxide
Particular sequence of DNA where replicatino begins - may be single of multiple

31. What is loss of heterozygosity and give an example
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
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
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
MRNA

32. Describe the location and fxn of the Na/K ATPase
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
UGA - UAA and UAG
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Oxalacetate

33. Patients with chronic granulomatous disease are at increased risk of infection From which kind of organisms
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
75 to 90 - cloverleaf
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
FISH

34. What are the two transgenic strategies in mice
25OHD3
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Liver and leafy veggies

35. delivers hepatic TGs to peripheral tissue - secreted by liver
VLDL
B6
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

36. What are the symptoms of vit A def
Locus heterogeneity - ocular albinism is x- linked recessive
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Tuberous sclerosis
Night blindness - dry skin

37. What does the CFTR channel do in the lungs - GI tract and skin
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Stop codon is recognized by release factor - and completed protein is released from ribosome
Karyotyping
Active secretion in lungs and GI - reabsorbs in skin

38. What is the main source of folate
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Foliage - small reserve in liver - eat green leaves
Hyperlipidemia

39. nucleotide repeat for fragile x
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Nature and severity of phenotype vary from 1 individual to another - NF type 1
APRT + PRPP
CGG

40. 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
Base + ribose + phosphate (3' -5') phosphodiester bond
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
MRNA
N to C

41. What does vit B3 def result in
PFK - rate limiting enzyme
They yield only acetyl - CoA equivalents
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Seals.

42. How do odd chain fatty acids participate in gluconeogenesis
After citruline
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Protein
HMP shunt

43. What is the origin of replication
Dec methionine - inc cystiene - inc B12/folate
FISH
Lactate
Particular sequence of DNA where replicatino begins - may be single of multiple

44. What is incomplete penetrence and give an example
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
GTP
Not all individuals with a mutant genotype show the mutant phenotype
SnRNPs

45. What is the wernicke - korsakoff clinical picture
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
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

46. What does Ehlers Danlos cause and why
Inhibits the Na/K pump by binding the K side
G6PD
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

47. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
CFTR gene - 7 - Phe 508
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Cyclin dependent kinases;constitutive and inactive
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

48. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Wobble
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Cre - lox system

49. Type I bone
Unwinds DNA template at replcation fork
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
BOne
Keep glutathione reduced so it can detoxify free radicals and peroxides

50. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
B-100 - CII and E
Familial hypercholesterolemia - hyperlipidemia type IIA
RER