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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. RNA poly can't proofread - but What can it do
Dopamine beta hydroxylase
Initiate chains
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Fibrofatty replacement of muscle - cardiac myopathy

2. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Glucose -6 phosphate
Mutated dystrophin gene - less severe - adolescence
Elastase - inhibited by alpha1 antitrypsin

3. An inability to convert orotic acid to UMP would be caused by a deficiency either of which two enzymes

4. Where is PEP carboxykinase found - What does it do - and What does it require
Acetoacetate and beta hydroxybutyrate
G6PD
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Basement membrane or basal lamina

5. What is dominant negative mutation and give an example
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
Anabolic processes as a supply of reducing equivalents
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

6. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
5' to 3'
Isocitrate dehydrogenase
Marasmus - muscle wasting

7. How do microtubules grow and collapse
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Inc vit B6
Grows slowly - collapses quickly
Phosphofructokinase 1

8. bilateral acoustic schwannomas - juvenile cataracts
NADH - NADPH - FADH2
Arg and his inc in histones Which bind negatively charged DNA
NF2 on chromosome 22
Wobble

9. What is the activated carrier for 1 carbon units
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Skin
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
THFs

10. How is orotic aciduria inherited
Only processed RNA
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
AR

11. What are the 4 assumption of the Hardy Weinberg law
Seals.
Mitochondria
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Conversion of NE to epi

12. What is the treatment for dec affinity of cystathionine synthase for pyroxidal phosphate
HMP shunt
Inc vit B6
Fed
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

13. Where is fructose 1 -6 bisphosphatase found and What does it do
ATP hyrdolysis couple to energetically unfavorable rxns
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
P2 +2pq+ = 1
Cytosol - F 1 -6 BP to fructose 6 Phosphate

14. Why enzyme breaks down elastin and what enzyme inhibits it
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Debranching enzyme
Elastase - inhibited by alpha1 antitrypsin
Glycogenolysis to form glucose

15. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
ADPKD
HMG- CoA synthase
Marfans

16. What is Retin A used topically for
Wrinkles and acne
Transmitted only through mother - all offspring of affected females may show signs of disease
BOne
Coenzyme A - lipoamide

17. In which direction is protein synthesized
Assistance of upper extremities to stand up
N to C
Basement membrane or basal lamina
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

18. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

19. What is used to diagnose muscular dystrophies
Polyneuritis - symmetrical muscle wasting
Liver - ovaries - seminal vesicles
Inc CPK and muscle biopsy
Binds to LDL receptor - mediates VLDL secretion

20. What 3 amino acids are necessary for purine synthesis
Glycine - aspartate - glutamine
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Glucose -6 phosphate
Result from phagocytic removal of heinz bodies my macs - G6PD def

21. What is the fxn of vit D
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Must be both activated and inactivated for cell cycle to progress
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Creat a nick in the helix to relieave supercoils created during replication

22. In what direction are DNA and RNA synthesized

23. What is NADPH's role inside RBCs
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
9+2 arrangement of microtubules
Keep glutathione reduced so it can detoxify free radicals and peroxides

24. What is the result of vit B5 def
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Oxalacetate
3' end (with CCA)
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

25. What happens in vit D excess
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

26. This is the site where negative regulators bind
Silencers
Conversion of NE to epi
Stop codon is recognized by release factor - and completed protein is released from ribosome
Neurofibromatosis type 1 (von Recklinghausens disease)

27. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
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

28. What is the activated carrier for phosphoryl
Liver and leafy veggies
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Particular sequence of DNA where replicatino begins - may be single of multiple
ATP

29. What are the findings in orotic aciduria
Hypoxanthine to xanthing and xanthine to uric acid
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Dec methionine - inc cystiene - inc B12/folate
APKD1 on chromosome 16

30. ADPKD is associated with What additional conditions
25OHD3
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Cleft palate - cardiac abnl - pregs test
Polycystic liver disease - berry aneurysm - mitral valve prolapse

31. 90% of ADPKD cases are due to a mutation In what gene
ATP and alanine
APKD1 on chromosome 16
4 under the floor
SAM

32. Mild Hurlurs + aggressive behavior no corneal clouding
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
1 ring
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

33. Acetyl - CoA carboxylase catalyzes what rxn
Site of steroid synthesis and detoxification of drugs and poisons
Inc melt - dec fluidity
Base + ribose + phosphate (3' -5') phosphodiester bond
Acetyl - CoA to malonyl - CoA (2C to 3C)

34. What are the reactants for glycolysis
Von Gierke's - Pompe - Cori - McArdle
Locus heterogeneity - ocular albinism is x- linked recessive
Diphyllobothrium latum
Glucose - 2Pi - 2ADP - 2NAD+

35. What does the golgi add to serine and threonine residues
Inc Cl - in sweat
O- oligosaccharaides
One
Core proteins

36. What is maternal PKU
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Flank pain - hematuria - HTN - progressive renal failure
Dopa decarboxylase
Mucus secreting globlet cells and antibody secreting plasma cells

37. In what cells do the respiratory burst occur
PMNs
Carbomoyl phosphate synthetase I
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

38. What does a southern blot use as its sample
DNA
Degradation of TG stored in adipocytes
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Eu - methionine - pro - formyl - methionine

39. What is the trinucleotide repeat in fragile X
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
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
MRNA - tRNA
CGG

40. Describe robertsonian translocation
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
VLDL
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

41. What is RNAi used for
DsRNA promotes degradation of target mRNA knocking down gene expression
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
CTG
CarTWOlage

42. How are the many staggered tropocollagen molecules reinforced
African Americans and Asians
Microtubules
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

43. Which carbon bears the triphosphate and the energy source for bond formation

44. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
ATP and alanine
Von gierkes - glucose 6 phosphatase
Catabolic processes to carry reducing equivalents away as NADH
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

45. Type III collagen
Malonyl coa
ATP hyrdolysis couple to energetically unfavorable rxns
Inc dicarboxylic acids - dec in glucose and ketones
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

46. Where is glucose 6 phosphatase found and What does it do
Exons
Pyruvate to oxaloacetate (3C to 4C)
In ER - glucose 6- P to glucose
1 -25 OH2 D3 = calcitriol

47. What is the limiting reagent in EtOH metabolism
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Neural tube
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
NAD+

48. What does amino acid catabolsim results in the formation of what?
HMP shunt
Activates LCAT
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Cartilage - hyaline - vitreous body - nucleus pulposus

49. colon becomes covered witih adenomatous polyps after puberty - progresses to colon cancer unless resected
FAP
Assistance of upper extremities to stand up
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
Hereditary spherocytosis

50. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Alanine
PCR - denaturation - annealing - elongation
ATP and alanine