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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. How does insulin inhibit glycogenolysis
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Arginine

2. What is the most abundant protein in the body
Phosphofructokinase 1
Collagen
Removal of N or C termal propeptides from zymogens to generate mature proteins
Glutamine PRPP amidotransferase

3. What does the TCA cycle produce per 1 acetyl CoA
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Connective tissue
Base + ribose
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

4. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
Cri du chat
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex

5. How do labile celss grow and regenerate and What are examples
Silencers
CGG
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

6. In which single strand DNA repair mechanism do specific endonucleases release the oligonucTIDE containing bases and DNA poly and ligase fill and reseal - and what disease occures when this is mutated
Bruton's agammaglobulinemia - wiskott - aldrich - fabrys disease - G6PD def - ocular albinism - Lesch - Nyhan syndrome - Duchenne and Becker Muscular Dystrophy - hunter's syndrome - hemophilia A and B
Microtubules
Von Gierke's - Pompe - Cori - McArdle
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light

7. Where do you find elastin and What does it do
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Glutamate
Vit K antagonist

8. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
THFs
Mutated dystrophin gene - less severe - adolescence
Removal of N or C termal propeptides from zymogens to generate mature proteins
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

9. What feedback inhibits hexokinase
Glucose -6 phosphate
Each codon specifies only 1 amino acid
Mediates chylomicron secretion
Q -

10. What does a defective Cl channel do
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
17 - 17 letters in von Recklinghausen
Accelearted muscle breakdown

11. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
32 - malate aspartate shuttle
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
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

12. What is sorbitol - how and why is it made
Nissl body - enzyme and NTs
Targets the proteins for lysosome
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Specific glycosylases - AP endonuclease

13. What happens in vit K def
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
9+2 arrangement of microtubules

14. What does a mischarge tRNA do
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Reads usual codon but inserts wrong AA
Glutamine PRPP amidotransferase
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

15. What does amino acid catabolsim results in the formation of what?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

16. Where is PEP carboxykinase found - What does it do - and What does it require
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
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Hyperlipidemia
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

17. What substance inside the cells replenishes NADPH
G6PD
NADPH
Glycogen synthase
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

18. What rxn does propionyl - CoA carboxylase catalyze
Dopamine beta hydroxylase
Familial hypercholesterolemia - hyperlipidemia type IIA
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
They yield only acetyl - CoA equivalents

19. What order kinetics does EtOH dehydrogenase have
Microtubules
Phosphofructokinase 1
Zero
Pyruvate - NAD+ - CoA

20. Where is glucokinase found - What are the Km and Vmax - and what induces it
Acetyl - CoA to malonyl - CoA (2C to 3C)
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Neurons

21. What does GFAP stain for
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Terminal regions - tropocollagen
Neuralgia
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver

22. What are cyclins
Vincritsine/vinblastine
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Huntingtons

23. What apolipoprotiens are on VLDL
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
Glycogen phosphorylase
B-100 - CII and E
Glucose -6 phosphate

24. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
ADPKD
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Skin
Krabbes - galactocerebrosidase - galactocerebroside - AR

25. What does apoE do
B-100 - CII and E
Mediates extra remnant take up
Biotin
Malonyl coa

26. What enzyme becomes essential in PKU
X linked frame shif mutation
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Tyrosine

27. What is the RDE of glycogenolysis
Consesus sequenec of base pairs
Glycogen phosphorylase
Lysine and arginine
Paclitaxel

28. What is the RDE of de novo pyrimidine synthesis
Debranching enzyme
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Carbomoyl phosphate synthetase II
Protein kinase A

29. what gene is implicated in fragile X syndrome - and What is the mutation
Vit K antagonist
Euchromatin
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
FMR1 gene - methylation - associated with chromosomal breakage

30. What are the 4 assumption of the Hardy Weinberg law
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Hereditary spherocytosis
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

31. What is the rate limiting enzyme in cholesterol synthesis
HMG- CoA (HMG- CoA to mevalonate
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
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
Polyneuritis - symmetrical muscle wasting

32. What does the vimentin stain for
Deamination
Connective tissue
Ribos first then deoxyribos with ribonucleotide reductase
PCR - denaturation - annealing - elongation

33. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Biotin
Essential fructosuria - fructokinase AR

34. Which direction does kinesin go
LDL
Inc glucagon - inc cAMP - inc PKA
Neg to pos
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

35. What two proteins make up microtubules and how are they arranged
Changed AA (convservative - new AA is similar in chemical structure)
Alpha and beta tubulin - dimers have two GTP bound
Glycogen phosphorylase
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

36. What is Retin A used topically for
Alanine
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Reads usual codon but inserts wrong AA
Wrinkles and acne

37. In mismatch repair - which strand is recognized and In what hereditary syndrome is this defective
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Scrutinizes - hydrolyzes the bond
Phenylalanine hydroxylase
Unmethylated - newly synthesized - HNPCC

38. What is the amino acid precursor for GABA and glutathione
Glycine - aspartate - glutamine
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Fed
Glutamate

39. characterize x linked recessive
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Neuralgia
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
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

40. How do fluoroquinolones work
Terminal regions - tropocollagen
Inhibit DNA gyrase specific for prokaryotic topoisomerase
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
4 under the floor

41. In prokaryotes - What does makes the different types of RNA
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
1 kind with multiple subunits
Seals.
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

42. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
Huntingtons
Heterochromatin = HighlyCondensed
Polyneuritis - symmetrical muscle wasting
Proline and lysine - vit C

43. What 3 steps in RNA processing occur after transcription

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44. Name 5 drugs that interfere with nucleotide synthesis
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

45. What is a silent mutation
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Same AA - often base change in 3rd position of codon (tRNA wobble)
Phenylketones in urine
B6

46. What is the treatment for dec affinity of cystathionine synthase for pyroxidal phosphate
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Lariat shape in order and remove intron precisely and join 2 exons
Inc vit B6
Glycine

47. What do def in in enzymes of gluconeogenesis cause
Mebendazole/thiabendazole
Removes phosphate group from substrate
Biotin
Hypoglycemia

48. How many ATP are created by aerobic metobolism of glucose in muslce via what shuttle
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
PMNs
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
30 - glycerol -3- phosphate shuttle

49. 90% of ADPKD cases are due to a mutation In what gene
Facial flushing
Debranching enzyme
APKD1 on chromosome 16
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

50. What are the results of CF on male fertility
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Abnormal protein folding - degradation before reaching cell surface
Males are infertile due to bilateral absence of vas deferens
Arg and his inc in histones Which bind negatively charged DNA