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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. Gene imprinting implies that How many alleles are active at a single locus
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
HMP shunt
One
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

2. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
Griseofulvin
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
AR
Diphyllobothrium latum

3. Which are the basic amino acids
HMG- CoA synthase
Liver and leafy veggies
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Arg - lys - his - arg is most basic - has has no charge at body pH

4. What is the RDE of fatty acid synthesis
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Failure to track objects or develop a social smile
Acetyl - CoA carboxylase (ACC)

5. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
IDL
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

6. What is the energy source after day 3 of starvation
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
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death
Citrate - acetyl coa from mito to cyto
Q -

7. In which direction is protein synthesized
Mitochondria
N to C
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
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

8. What is the RDE of TCA cycle
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Epithelial cells
5' of the incoming nucleotide
Isocitrate dehydrogenase

9. characterize x linked dominant
NADH - NADPH - FADH2
Acetoacetate and beta hydroxybutyrate
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
30 - 50 - 70

10. delivers hepatic TGs to peripheral tissue - secreted by liver
Inc Cl - in sweat
Vincritsine/vinblastine
Glucose 6 phosphatase
VLDL

11. What is linkage disequilibrium
Keep glutathione reduced so it can detoxify free radicals and peroxides
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Acetyl - CoA

12. What are the symptoms of vit A def
Night blindness - dry skin
Familial hypercholesterolemia - hyperlipidemia type IIA
SNP
Hypoxanthine to xanthing and xanthine to uric acid

13. What substances are uncouling agents
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
2 -4 DNP - aspirin
Cartilage - hyaline - vitreous body - nucleus pulposus
Unmethylated - newly synthesized - HNPCC

14. What causes B12 def
Dec methionine - inc cystiene - inc B12/folate
32 - malate aspartate shuttle
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Colchicine

15. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Intermediate filaments
LDL
Removes phosphate group from substrate
Stored ATP - creatine phosphate - anaerobic glycolysis

16. What is regeneration of methionine depedent on...
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
Fibroblast
In ER - glucose 6- P to glucose
B12 and folate

17. What is the fxn of vit K
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Alpha 1 -4 glucosidase
Glutamine PRPP amidotransferase
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

18. What does a dehydrogenase do
Ribose 5- P to PRPP
Oxidizes substrate
Schwann cells - lens - retina - kidneys
Intermediate filaments

19. caf
Fibroblast
Neurofibromatosis type 1 (von Recklinghausens disease)
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
NADPH

20. What is the name is fxn of vit B3
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Niacin - constituent of NAD and NADP - derived from tryptophan
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Essential fructosuria - fructokinase AR

21. What are covalent alterations
Phosphorylation - glycosylation - hydroxylation
Met - val - arg his
Myeloperoxidase
Cofactor for LPL

22. 90% of ADPKD cases are due to a mutation In what gene
Orotic acid to UMP
Post to neg
30 - glycerol -3- phosphate shuttle
APKD1 on chromosome 16

23. What does Ehlers Danlos cause and why
Orotate precursor - with PRPP added later
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

24. What are purines made from
IMP precursor
Intermediate filaments
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Protein

25. Type I collagen
O- oligosaccharaides
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Inc dicarboxylic acids - dec in glucose and ketones

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

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27. What is the activated carrier for aldehyddes
Oxidizes substrate
TTP
Marasmus - muscle wasting
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons

28. What is the RDE of gluconeogenesis
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Fructose 1 -6 bisphosphate
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

29. What does acetyl - CoA become before becoming palmitate
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Lysine and arginine
UDP glucose pyrophosphorylase
Sucrose = glucose + fructose - lactose = glucose + galactose

30. How is ATP used by the cell
Glutamine PRPP amidotransferase
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
ATP hyrdolysis couple to energetically unfavorable rxns
Cytosol - F 1 -6 BP to fructose 6 Phosphate

31. What two proteins make up microtubules and how are they arranged
Ca/calmodulin in muscle to coordinate with muscle activity
Deamination
MRNA - tRNA
Alpha and beta tubulin - dimers have two GTP bound

32. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Intermediate filaments
Oligomycin
Leu - lys
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine

33. What does aminoacyl tRNA synthetase do the AA before and after it binds to tRNA - and what happens if it's the wrong the match
Scrutinizes - hydrolyzes the bond
Hereditary spherocytosis
GTP
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

34. Where is fructose 1 -6 bisphosphatase found and What does it do
SAM
Alpha1 antitrypsin
High output cardiac failure - dilated cardiomyopathy - edema
Cytosol - F 1 -6 BP to fructose 6 Phosphate

35. What does degenerate/rundant genetic code refer to...
Targets the proteins for lysosome
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
More than 1 codon may code for the same amino acid
TTP

36. What is RNAi used for
32 - malate aspartate shuttle
Promotor - TATA box - and CAAT box - AT rich
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
DsRNA promotes degradation of target mRNA knocking down gene expression

37. How does ethanol induce hypoglycemia
Lysine and arginine
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
Dopa decarboxylase
Creat a nick in the helix to relieave supercoils created during replication

38. What is the defect in I- hyperchylomicronemia
Acetyl - CoA carboxylase (ACC)
Cyclin dependent kinases;constitutive and inactive
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
B48 - AIV - CII - E

39. In prokaryotes - What does makes the different types of RNA
1 kind with multiple subunits
After citruline
PMNs
Alpha1 antitrypsin

40. What is the TX for PKU
ADPKD
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Pseudomonas and s aureus

41. Where is glucokinase found - What are the Km and Vmax - and what induces it
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Protein
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Dermatitis - enteritis - alopecia - adrenal insuff

42. What enzyme turns ROS to H2O2
17 - 17 letters in von Recklinghausen
Keep glutathione reduced so it can detoxify free radicals and peroxides
Superoxide dismutase
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

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

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44. What is the rate determining enzyme (RDE) of glycolysis
After citruline
Result from phagocytic removal of heinz bodies my macs - G6PD def
Von hippel lindau - 3
Phosphofructokinase 1

45. Which amino acids are elastin rich in
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
Proline and glycine (non glycosylated forms)
Euchromatin
Degradation of TG remaining in IDL

46. What is the defect in cystinuria
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
PFK - rate limiting enzyme

47. 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
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
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
Phenylketones in urine
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

48. What is anticipation and give an example
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
No
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

49. What are the purely ketogenic amino acids
Free ribosomes
Leu - lys
NADPH
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

50. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
Dec DNA - dec lymphos leads to SCID
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
APKD1 on chromosome 16
2 -4 DNP - aspirin