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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. How does warfarin work
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Wobble
Vit K antagonist

2. What is the RDE of cholesterol synthesis
AR
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
HMG- CoA reductase

3. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
SnRNPs and other proteins
N to C
DTMP
Methionine encode by only 1 codon (AUG)

4. How do aminoglycosides work
Rotenone - CN- - antimycin A - CO
II - VII - IX - X (1972) protein C and S
B100 and E
By inhibiting formation of the initiation complex and cause misreading of mRNA

5. What is the breakdown product of dopamine
APC on chromosome 5
HVA
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Acetoacetate and beta hydroxybutyrate

6. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Creat a nick in the helix to relieave supercoils created during replication
Anabolic processes as a supply of reducing equivalents

7. In prokaryotes - What does makes the different types of RNA
Krabbes - galactocerebrosidase - galactocerebroside - AR
1 kind with multiple subunits
Breaks down acyl - coa to acetyl coa groups in mito
ADPKD

8. What converts tyrosine to DOPA
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Tryosine hydroxylase

9. What makes up a nucleoside
Base + ribose
Cytosol
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
1 kind with multiple subunits

10. Why is G6PD def more common among patients of african decent
Protective against malaria
Degredation of TG circulating in chylomicrons and VLDLs
Alpha1 antitrypsin
ATP hyrdolysis couple to energetically unfavorable rxns

11. Why is albinism inheritnace varialbe due to...
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Von Gierke's - Pompe - Cori - McArdle
Locus heterogeneity - ocular albinism is x- linked recessive
Euchromatin

12. What converts DOPA to dopamine
Dopa decarboxylase
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Von gierkes - glucose 6 phosphatase
Ketone - methyl

13. What are uncoupling agents
FISH
Karyotyping
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
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

14. Is there any requirement for homology in NHEJ
No - its non homologous
Wernicke - korsakoff - dry and wet beriberi
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

15. What happens in vit K def
MRNA - tRNA
1 ring
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

16. What is the RDE of de novo pyrimidine synthesis
CAG
Mediates chylomicron secretion
Carbomoyl phosphate synthetase II
Oxalacetate

17. Where is PEP carboxykinase found - What does it do - and What does it require
Transmitted only through mother - all offspring of affected females may show signs of disease
Avidin
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

18. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
3' end (with CCA)
4 under the floor
Liver - also in kidney and gut epithelium
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

19. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
RRNA
UDP glucose pyrophosphorylase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Semiconservative - continuous and discontinuous strands (okazaki fragments)

20. What amino acid makes up most of the octamer
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Lysine and arginine
Neurons
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

21. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
HMG- CoA (HMG- CoA to mevalonate
MRNA
Inhibits RNA polymerase II - found in death cap mushrooms
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

22. How does ouabain work
Dopamine beta hydroxylase
Inhibits the Na/K pump by binding the K side
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

23. What residues are hydroxylated in step 2 of collagen synthesis - and What does this require
Assistance of upper extremities to stand up
Proline and lysine - vit C
Arg and his inc in histones Which bind negatively charged DNA
B48 - AIV - CII - E

24. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
1 -25 OH2 D3 = calcitriol
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

25. What are the teratogenic effects of vit A and What test must be ordered before starting a woman on isotreitinoin for severe acne
Phosphorylation - glycosylation - hydroxylation
Site of steroid synthesis and detoxification of drugs and poisons
Exercise: inc NAD/NADH - inc ADP - inc Ca
Cleft palate - cardiac abnl - pregs test

26. What does a defective Cl channel do
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Q -
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

27. How do you diagnose CFTR
Cytosol
Marasmus - muscle wasting
Inc Cl - in sweat
B100 and E

28. What does the start codon code for in eukaryotes and prokaryotes
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
32 - malate aspartate shuttle
Eu - methionine - pro - formyl - methionine
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS

29. When does aspartate enter the urea cycle
After citruline
III - joint dislocation - anuerysms - organ rupture
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year
Cri du chat

30. What 3 amino acids are necessary for purine synthesis
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Glycine - aspartate - glutamine

31. What reaction does adenosine deaminase normally catalyze
Terminal regions - tropocollagen
Muscle
Tyrosine
Adenosine to inosine

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

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33. What causes Edwards syndrome and What is it
Terminal regions - tropocollagen
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
One
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year

34. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
MEN - 2A and 2B with ret gene
Dermatitis - enteritis - alopecia - adrenal insuff
LDL
RRNA

35. What does a carboxylase do
HVA
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Adds 2 carbon with the help of biotin

36. What converts dopamine to NE
Dopamine beta hydroxylase
SAM
Glucose -6 phosphate
X- linked recessive

37. What is the activated carrier for Co2
X- linked recessive
Acetly- CoA - CO2 - NADH
Biotin
Microtubules

38. What is the activated carrier for Acyl
Autosomal recessive diseases
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Coenzyme A - lipoamide
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

39. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
ADPKD
HMG- CoA (HMG- CoA to mevalonate
Base + ribose
Heterochromatin = HighlyCondensed

40. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Glucose - 2Pi - 2ADP - 2NAD+
Oxalacetate
Flagella - cilia - mitotic spindles
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

41. What activates the pyruvate dehydrogenase complex
3' end (with CCA)
Exercise: inc NAD/NADH - inc ADP - inc Ca
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

42. What are the clinical features of I cell diesase
Stored ATP - creatine phosphate - anaerobic glycolysis
II - VII - IX - X (1972) protein C and S
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

43. What two rxns in in glycolysis require ATP
30 - glycerol -3- phosphate shuttle
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Post to neg

44. Which antihelminthe drugs work on microtubules
F16BP
Palate - facial and cardiac defects
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Mebendazole/thiabendazole

45. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Williams syndrome
Inc insulin - dec cAMP - dec PKA
F16BP

46. What are the findings in orotic aciduria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
9+2 arrangement of microtubules
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Colchicine

47. What do the single stranded binding proteins do
Prevent strands from reannealing
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
DNA
GAA

48. What ribosomes do prokaryotes have
Citrate - acetyl coa from mito to cyto
B100
Cytosol - F 1 -6 BP to fructose 6 Phosphate
30 - 50 - 70

49. What enzyme becomes essential in PKU
Tyrosine
GTP
Carnitine acyltransferase I
Flagella - cilia - mitotic spindles

50. What are the water soluble vitamins - which ones are stored
Proline and glycine (non glycosylated forms)
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase