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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. Why can't muscle produce in gluconeogenesis
Inc melt - dec fluidity
Von Gierke's - Pompe - Cori - McArdle
Lacks glucose 6 phophatase
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

2. What does NADPH oxidase deficiency result in and why
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Wernicke - korsakoff - dry and wet beriberi
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Proline and lysine - vit C

3. What does apoB48 do
Oxidative is irreversible
Mediates chylomicron secretion
FISH
II - VII - IX - X (1972) protein C and S

4. 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
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Ile - phe - thr - trp
Transmitted only through mother - all offspring of affected females may show signs of disease
One

5. characterize x linked dominant
Acetoacetate and beta hydroxybutyrate
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Neuralgia
Met - val - arg his

6. What does a western blot use for its sample
Nine
Degradation of TG remaining in IDL
Paclitaxel
Protein

7. What is the RDE of glycogen synthesis
Prevent strands from reannealing
Result from phagocytic removal of heinz bodies my macs - G6PD def
Elastase - inhibited by alpha1 antitrypsin
Glycogen synthase

8. Where is fructose 1 -6 bisphosphatase found and What does it do
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Liver - also in kidney and gut epithelium

9. In what cell is collagen synthesis initiated
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Pseudomonas and s aureus
Fibroblast
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

10. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Oxalacetate
O- oligosaccharaides
Glycine
Fibrofatty replacement of muscle - cardiac myopathy

11. What causes biotin def
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Adenosine to inosine
Antibiotic use or excessive ingestion of raw eggs
Neural tube

12. 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
Protein kinase A
Activates LCAT
Scrutinizes - hydrolyzes the bond
Active secretion in lungs and GI - reabsorbs in skin

13. What are purines made from
IMP precursor
40 - 60 - 80
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

14. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
RRNA
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Proton gradient
Tuberous sclerosis

15. In what cells do the respiratory burst occur
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
Stored ATP - creatine phosphate - anaerobic glycolysis
Disorder of aromatic amino acid metabolism
PMNs

16. nucleotide repeat for fragile x
P2 +2pq+ = 1
Lysine and arginine
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
CGG

17. In which state is FBPase -2 active
Fasting
Comlex II
Prevent strands from reannealing
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR

18. What is sorbitol - how and why is it made
Fasting
They yield only acetyl - CoA equivalents
Read from a fixed starting point as a continuous sequence of bases
Alcohol version of glucose - can trap glucose in cell - aldose reductase

19. What do DNA topoisomerases do
Creat a nick in the helix to relieave supercoils created during replication
Disease
Unmethylated - newly synthesized - HNPCC
Von gierkes - glucose 6 phosphatase

20. What is the energy source for translocation
X- linked recessive
Hereditary spherocytosis
APKD1 on chromosome 16
GTP

21. What does the golgi add to serine and threonine residues
Dopamine beta hydroxylase
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
O- oligosaccharaides

22. What converts limit dextran to glucose
EtOH dehydrogenase and acetaldehyde dehydrogenase
Von hippel lindau - 3
Debranching enzyme
Glycolysis and aerobic respiration

23. What enzyme results in classic galactosemia and What is the clinical
Fibroblast
Alpha1 antitrypsin
HMP shunt
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

24. What is the complication of cystinuria
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Diphyllobothrium latum
Orotate precursor - with PRPP added later
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

25. What is the most common urea cycle disorder and What is the mode of inheritance?
O- oligosaccharaides
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Histidine
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

26. What is the RDE of de novo purine synthesis
Glutamine PRPP amidotransferase
HVA
CarTWOlage
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

27. How many rings do purines have
Core proteins
2 rings
Phenylalanine hydroxylase
Anabolic processes as a supply of reducing equivalents

28. What is the defect in cystinuria
Grows slowly - collapses quickly
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
1 ring
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

29. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
RNA poly II
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

30. What causes maple syrup urine disease and What does it lead to...
Degredation of TG circulating in chylomicrons and VLDLs
Dopa decarboxylase
Microtubules
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

31. What does acetyl - CoA become before becoming palmitate
Protective against malaria
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
CGG
Methionine encode by only 1 codon (AUG)

32. Where is pyruvate carboxylase found - What does it do - What does it require amd What activates it
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Histidine
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

33. What is the RDE of glycogenolysis
Consesus sequenec of base pairs
Dec methionine - inc cystiene - inc B12/folate
Glycogen phosphorylase
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue

34. What are the findings in PKU
Activates LCAT
Dopa decarboxylase
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Muscle

35. In which state is PFK-2 active
Alpha 1 -4 glucosidase
Each codon specifies only 1 amino acid
NADH - NADPH - FADH2
Fed

36. What does vit B3 def result in
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE
GAA
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Paclitaxel

37. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
PCR - denaturation - annealing - elongation
OTC has hyperammonemia - orotic aciduira does not
Disorder of aromatic amino acid metabolism
Anabolic processes as a supply of reducing equivalents

38. What causes Marfan syndrome
Defect in fibrillin
Cre - lox system
NAD+
Debranching enzyme

39. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Disorder of aromatic amino acid metabolism
Alanine
Same AA - often base change in 3rd position of codon (tRNA wobble)
Glucose - 2Pi - 2ADP - 2NAD+

40. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
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
NADPH
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Phosphorylation - glycosylation - hydroxylation

41. What converts DOPA to dopamine
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Dopa decarboxylase
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Targets the proteins for lysosome

42. What are the physical findings of fragile x syndrome
CGG
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 - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
PMNs

43. What is NADPH used for
CTG
DTMP
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Anabolic processes as a supply of reducing equivalents

44. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Polyneuritis - symmetrical muscle wasting
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
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

45. What does apoB100 do
Fed
Antibiotic use or excessive ingestion of raw eggs
Binds to LDL receptor - mediates VLDL secretion
X linked frame shif mutation

46. What is the Hardy Weinberg disease prevalence equation
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
Lariat shape in order and remove intron precisely and join 2 exons
P2 +2pq+ = 1
Particular sequence of DNA where replicatino begins - may be single of multiple

47. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
Dopa decarboxylase
Krabbes - galactocerebrosidase - galactocerebroside - AR
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
AR

48. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Antioxidant - protects RBCs and membrances from free radical damage
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Liver hepatocytes and steroid producing cells of the adrenal cortex

49. What is codominance and give an example
Huntingtons
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Neither of 2 alleles is dominant - blood groups
Supply sufficient glucose to brain and RBCs and to preserve protein

50. What does a kinase do
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Inc insulin - dec cAMP - dec PKA
Uses ATP to add high energy phophate group onto substrate
Dopamine beta hydroxylase