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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 does the CFTR channel do in the lungs - GI tract and skin
Active secretion in lungs and GI - reabsorbs in skin
Inhibits RNA polymerase II - found in death cap mushrooms
Comlex II
Neurofibromatosis type 1 (von Recklinghausens disease)

2. What are the characteristics of angelmans syndrome and How does it occur
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
UGA - UAA and UAG

3. What happens to glycogen in the liver
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
DsRNA promotes degradation of target mRNA knocking down gene expression
PMNs

4. What initiates protein synthesis
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Anabolic processes as a supply of reducing equivalents
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Specific glycosylases - AP endonuclease

5. What tissues have both enzymes of sorbitol metabolism
Liver - ovaries - seminal vesicles
TTP
L form
Tryosine hydroxylase

6. What does acetyl - CoA become before becoming palmitate
Enhancers
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Von Gierke's - Pompe - Cori - McArdle
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

7. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Familial hypercholesterolemia - hyperlipidemia type IIA
Night blindness - dry skin
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Hypoglycemia

8. What two proteins make up microtubules and how are they arranged
Alpha and beta tubulin - dimers have two GTP bound
By inhibiting formation of the initiation complex and cause misreading of mRNA
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

9. What is the prevalence of an X- linked recessive disease in males and in females
ATP
Q -
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Phenytoin - MTX - and sulfonamides

10. How does patients present with ADPKD
Flank pain - hematuria - HTN - progressive renal failure
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
ATP and alanine
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

11. What is the source of energy in the fasting state between meals
Eu - methionine - pro - formyl - methionine
Dermatitis - alopecia - enteritis
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Breaks down acyl - coa to acetyl coa groups in mito

12. caf
Neurofibromatosis type 1 (von Recklinghausens disease)
Malonyl coa
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Exons

13. What part of the pre mRNA contains the actual genetic information coding for protein
Exons
Cyclin dependent kinases;constitutive and inactive
Modifies N- oligosaccharides
Removes phosphate group from substrate

14. What makes up a nucleoside
Base + ribose
ATP and methionine
AMP - fructose 2 -6 BP
Read from a fixed starting point as a continuous sequence of bases

15. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
3' end (with CCA)
Mcardle's - skeletal muscle glycogen posphorylase
Metanephrine
Cri du chat

16. what disease can cause pellagra
Neg to pos
Hyperlipidemia
Robertsonian translocation and mosaicism
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

17. What is the function of folic acid
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Degradation of TG stored in adipocytes
Base + ribose
Nonsense > missense > silent

18. What is the RDE of de novo pyrimidine synthesis
Carbomoyl phosphate synthetase II
30 - glycerol -3- phosphate shuttle
Dec methionine - inc cystiene - inc B12/folate
Avidin

19. What is variable expression and What is an example
Nature and severity of phenotype vary from 1 individual to another - NF type 1
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Targets the proteins for lysosome

20. in a 100 meter sprint Where does energy come from
Cleft palate - cardiac abnl - pregs test
Stored ATP - creatine phosphate - anaerobic glycolysis
P2 +2pq+ = 1
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol

21. What are CDKs
Cyclin dependent kinases;constitutive and inactive
NF2 on chromosome 22
Inc melt - dec fluidity
Dermatitis - enteritis - alopecia - adrenal insuff

22. In a 1000 meter run - Where does energy come from
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Same as sprint + OXPHOS
SNP

23. What is the treatment for cystathionine synthase def
Glycogenolysis to form glucose
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Dec methionine - inc cystiene - inc B12/folate
Coenzyme A - lipoamide

24. What enzyme converts adenine to AMP
GAA
Flagella - cilia - mitotic spindles
APRT + PRPP
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

25. How is vit D stored
Coenzyme A - lipoamide
25OHD3
OTC has hyperammonemia - orotic aciduira does not
Zero

26. How does cytosine become uracil
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Deamination
Removal of N or C termal propeptides from zymogens to generate mature proteins
Same AA - often base change in 3rd position of codon (tRNA wobble)

27. What are ketone bodies made from - where are they metabolized and how are they excreted
HGPRT - defective purine salvage - excess uric acid production
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
CAG
Flank pain - hematuria - HTN - progressive renal failure

28. Infection with what organism can cause B12 def
Diphyllobothrium latum
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Wobble
Collagen

29. What does vit C def cause
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Niacin - constituent of NAD and NADP - derived from tryptophan
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

30. What apolipoproteins are on IDL
B100 and E
Attachment of ubiquitin to defective proteins tag them for breakdown
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Nature and severity of phenotype vary from 1 individual to another - NF type 1

31. What substance inside the cells replenishes NADPH
B100
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Tyrosine
G6PD

32. 1 g of protein or cabrohydrate = ?kcal
Four
Inc Cl - in sweat
SAM
Only processed RNA

33. Type I collagen
Krabbes - galactocerebrosidase - galactocerebroside - AR
Initiate chains
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Antibiotic use or excessive ingestion of raw eggs

34. Giving folate during early pregnancy is important to prevent what birth defects
Neural tube
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
APRT + PRPP

35. What is sorbitol - how and why is it made
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Terminal regions - tropocollagen

36. What is the RDE of gluconeogenesis
After citruline
Arginine
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Fructose 1 -6 bisphosphate

37. What is a nonsense mutation
Change resulting in early stop codon
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
Ketone - methyl
Consesus sequenec of base pairs

38. What fxn does glucokinase serve in the liver
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Antioxidant - protects RBCs and membrances from free radical damage
Infection - free radicals generated by inflammatory response

39. What order kinetics does EtOH dehydrogenase have
B-100 - CII and E
Zero
L form
THFs

40. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Achondroplasia
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

41. How does warfarin work
Vit K antagonist
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
B6

42. What is the amino acid precursor for histamine
Site of steroid synthesis and detoxification of drugs and poisons
Histidine
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
17 - 17 letters in von Recklinghausen

43. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Removes phosphate group from substrate
Makes RNA primer on which DNA poly III can initiate replication
Active secretion in lungs and GI - reabsorbs in skin
Hereditary spherocytosis

44. How does ouabain work
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
Alkaptonuria - may have debiliating arthralgias
Inhibits the Na/K pump by binding the K side
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

45. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Lysine and arginine
Carnitine acyltransferase I
Fibrofatty replacement of muscle - cardiac myopathy
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle

46. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Schilling test
Hypoglycemia

47. In a marathon Where does energy come from
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Glycogen and FFA oxidation; glucose conserved for final sprinting
Met - val - arg his

48. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Uses ATP to add high energy phophate group onto substrate
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Keep glutathione reduced so it can detoxify free radicals and peroxides
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

49. What happens in folate def
Failure to track objects or develop a social smile
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Orotate precursor - with PRPP added later
Mcardle's - skeletal muscle glycogen posphorylase

50. delivers hepatic TGs to peripheral tissue - secreted by liver
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
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
B100 and E
VLDL