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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 CETP do
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Glycogen synthase
Dermatitis - enteritis - alopecia - adrenal insuff

2. bilateral - massive enlargement of of kidneys due to multiple large cysts
ADPKD
EtOH dehydrogenase and acetaldehyde dehydrogenase
Degradation of TG stored in adipocytes
Changed AA (convservative - new AA is similar in chemical structure)

3. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
NF2 on chromosome 22
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

4. What is regeneration of methionine depedent on...
Four
B12 and folate
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Inhibits the Na/K pump by binding the K side

5. What enzyme converts adenine to AMP
Activates LCAT
Removal of N or C termal propeptides from zymogens to generate mature proteins
APRT + PRPP
Chylomicrons

6. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Active secretion in lungs and GI - reabsorbs in skin
1 -25 OH2 D3 = calcitriol
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR

7. What does degenerate/rundant genetic code refer to...
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
More than 1 codon may code for the same amino acid
CarTWOlage
Ribos first then deoxyribos with ribonucleotide reductase

8. what findings are associated with marfans
HDL
Promotor - TATA box - and CAAT box - AT rich
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two

9. What happens in vit D def
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Transfers methyl units
Citrate - acetyl coa from mito to cyto
Chylomicrons

10. pyruvate carboxylase catalyzes what rxn
Pyruvate to oxaloacetate (3C to 4C)
TRNA
HMG- CoA (HMG- CoA to mevalonate
Consesus sequenec of base pairs

11. Broadly - What can cause fat - soluble vitamin deficiencies
UGA - UAA and UAG
Malapsorption syndromes like sprue or CF or mineral oil intake
BOne
Tuberous sclerosis

12. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Oxidized hemoglobin precipiated within RBCs
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

13. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Anabolic processes as a supply of reducing equivalents
Inc glucagon - inc cAMP - inc PKA
1 kind with multiple subunits
2 -4 DNP - aspirin

14. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Scrutinizes - hydrolyzes the bond
Orotic acid to UMP
UDP glucose pyrophosphorylase
Marfans

15. What is the function and name of vit B6
75 to 90 - cloverleaf
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
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Hereditary spherocytosis

16. What substance accumulates in galactokinase def and What is the clinical picture
Neg to pos
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Glycogenolysis to form glucose
Hyperlipidemia

17. What substance inside the cells replenishes NADPH
Seals.
G6PD
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Dec DNA - dec lymphos leads to SCID

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

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19. In what cells do the respiratory burst occur
Malonyl coa
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
PMNs
Glycogen phosphorylase

20. What two enzymes are involved in EtOH metabolism
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Fasting
EtOH dehydrogenase and acetaldehyde dehydrogenase
NADH - NADPH - FADH2

21. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
Catabolic processes to carry reducing equivalents away as NADH
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
EtOH dehydrogenase and acetaldehyde dehydrogenase

22. How does ouabain work
Foliage - small reserve in liver - eat green leaves
Inhibits the Na/K pump by binding the K side
GAA
Cytosol - F 1 -6 BP to fructose 6 Phosphate

23. What does a northern blot use as its sample
By inhibiting formation of the initiation complex and cause misreading of mRNA
RNA
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Infection - free radicals generated by inflammatory response

24. What polar group does guanine have - and what non polar group does thymine have
Polyneuritis - symmetrical muscle wasting
RRNA
Ketone - methyl
Rb and p53

25. What does commaless - nonoverlapping genetic code refer to...
Polyneuritis - symmetrical muscle wasting
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Liver - also in kidney and gut epithelium
Read from a fixed starting point as a continuous sequence of bases

26. What does cytokeratin stain for
Phenylketones in urine
Epithelial cells
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Liver - ovaries - seminal vesicles

27. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
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

28. What are the symptoms of vit A excess
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Transmitted only through mother - all offspring of affected females may show signs of disease

29. What is the Name and function of vit B1
Silencers
Huntingtons
Debranching enzyme
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

30. How is Lesch Neyhan inherited
Marfans
X- linked recessive
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

31. Which anticancer drugs work on microtubules
Vincritsine/vinblastine
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Alpha 1 -6 and alpha 1 -4
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex

32. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
OTC has hyperammonemia - orotic aciduira does not
Consesus sequenec of base pairs
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
B48 - AIV - CII - E

33. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Marasmus - muscle wasting
PFK - rate limiting enzyme
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

34. What converts dopamine to NE
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
Alpha - ketoglutarate dehydrogenase complex
ATP
Dopamine beta hydroxylase

35. How does chloramphenicol work
Glycine - aspartate - glutamine
Purines= A - G pyrimidine = C - T (U)
Inhibits 50S peptidyltransferase
Williams syndrome

36. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Orotic acid to UMP
Histidine

37. What induces pyruvate kinase
F16BP
UDP glucose pyrophosphorylase
Diphyllobothrium latum
LCAT (lecithin cholesterol acyltransferase)

38. Where is glucokinase found - What are the Km and Vmax - and what induces it
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Diphyllobothrium latum
Antioxidant - protects RBCs and membrances from free radical damage

39. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Oxidative and nonoxidative - no ATP produced or used
Mediates extra remnant take up

40. What is the longest time of RNA and shortest
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
RRNA
MRNA - tRNA
RNA

41. What is the activated carrier for aldehyddes
Unwinds DNA template at replcation fork
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
TTP
Avidin

42. What does fomepizole do
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

43. The pyruvate dehydrogenase complex serves In what reaction: products
Acetly- CoA - CO2 - NADH
Antibiotic use or excessive ingestion of raw eggs
Result from phagocytic removal of heinz bodies my macs - G6PD def
Williams syndrome

44. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Medial dorsal nucleus of thalamus - mamillary bodies
Glutamine PRPP amidotransferase
Fibrofatty replacement of muscle - cardiac myopathy

45. Milder form of type I with nl blood lactate levels - dz and enzyme

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46. What is the breakdown product of epi
Metanephrine
GAA
Diphyllobothrium latum
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE

47. What are the findings in Lesch - Nyhan
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Silencers
More than 1 codon may code for the same amino acid

48. What does Ehlers Danlos cause and why
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
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
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
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

49. What are the clinical features of I cell diesase
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
VMA
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

50. What does the start codon code for in eukaryotes and prokaryotes
Eu - methionine - pro - formyl - methionine
X- linked recessive
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Targets the proteins for lysosome