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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. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Glutamate
IDL
Arg and his inc in histones Which bind negatively charged DNA

2. What happens in vit D excess
Disorder of aromatic amino acid metabolism
32 - malate aspartate shuttle
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

3. What else can phosphoylate phosphorylase kinase
Ca/calmodulin in muscle to coordinate with muscle activity
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Neuralgia
P2 +2pq+ = 1

4. What is the function of folic acid
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
ATP
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

5. What is the amino acid precuros for niacin and serotonin/melatonin
Tryptophan
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Binds 50S - blocking translocation

6. What is the mutation in beckers muscular dystrophy - What is the severity and time of onset
N to C
Exercise: inc NAD/NADH - inc ADP - inc Ca
Mutated dystrophin gene - less severe - adolescence
Mucus secreting globlet cells and antibody secreting plasma cells

7. What does an umabiguous genetic code refer to...
Avidin
Each codon specifies only 1 amino acid
Reads usual codon but inserts wrong AA
Essential fructosuria - fructokinase AR

8. What does fomepizole do
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Transmitted only through mother - all offspring of affected females may show signs of disease
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

9. What substances inhibit phosphofructokinase -1
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
HDL
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
ATP - citrate

10. In what cells do the respiratory burst occur
PMNs
The triphosphate bond
MEN - 2A and 2B with ret gene
Prevent strands from reannealing

11. What is the Hardy Weinberg disease prevalence equation
P2 +2pq+ = 1
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

12. developmental delay - gargoylism - airway obstruction - corneal clouding - hepatosplenomegaly
Griseofulvin
Muscle
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

13. What is the purpose of the HMP shunt
MEN - 2A and 2B with ret gene
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Removal of N or C termal propeptides from zymogens to generate mature proteins

14. What bone disorder has x linked dominant inheritance
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Glycogen and FFA oxidation; glucose conserved for final sprinting
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR

15. What is mosaicism and give an example
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
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Skin

16. What is the energy source after day 3 of starvation
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
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
Flagella - cilia - mitotic spindles
O- oligosaccharaides

17. What 3 syndromes are associated with vit B1 def
Wernicke - korsakoff - dry and wet beriberi
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Inc dicarboxylic acids - dec in glucose and ketones

18. What does Adenosine deaminase deficiency cause a build up of - and What does that lead to?
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Inc insulin - dec cAMP - dec PKA
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Met - val - arg his

19. Which direction does dynein go
1 kind with multiple subunits
Post to neg
N to C
Attachment of ubiquitin to defective proteins tag them for breakdown

20. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
32 - malate aspartate shuttle
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
PCR - denaturation - annealing - elongation
One

21. In eukaryotes - What does RNA poly I make
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Phenylalanine hydroxylase
RRNA
Actin and myosin

22. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
After day 1
Defect in fibrillin
Karyotyping
Orotic acid to UMP

23. What is the energy source in the fed state right after a meal
Glycolysis and aerobic respiration
B100 and E
Cyclin dependent kinases;constitutive and inactive
Hypoglycemia

24. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Oxidizes substrate
G6PD
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Lactate

25. How does cytosine become uracil
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
FISH
Deamination
Malapsorption syndromes like sprue or CF or mineral oil intake

26. What does helicase do
Unwinds DNA template at replcation fork
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Cyclin dependent kinases;constitutive and inactive
X- linked recessive

27. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
Site of steroid synthesis and detoxification of drugs and poisons
CarTWOlage
HGPRT - defective purine salvage - excess uric acid production
Inhibit DNA gyrase specific for prokaryotic topoisomerase

28. What is NADPH's role inside RBCs
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Schilling test
X- linked recessive
Keep glutathione reduced so it can detoxify free radicals and peroxides

29. What is the complication of cystinuria
Oral uridine administration
LDL
Glucose 6 phosphate dehydrogenase (G6PD)
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

30. What causes Marfan syndrome
Achondroplasia
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
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Defect in fibrillin

31. What happens in elongation of protein synthesis

32. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Acetyl - CoA to malonyl - CoA (2C to 3C)
Essential fructosuria - fructokinase AR
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
By inhibiting formation of the initiation complex and cause misreading of mRNA

33. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Males are infertile due to bilateral absence of vas deferens
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Semiconservative - continuous and discontinuous strands (okazaki fragments)

34. What does the primary transcript combine with to form the spliceosome
One
Activates LCAT
SnRNPs and other proteins
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

35. How is ATP used by the cell
Foliage - small reserve in liver - eat green leaves
Acetoacetate and beta hydroxybutyrate
ATP hyrdolysis couple to energetically unfavorable rxns
Nine

36. Pts with albinism are at inc risk For what cancer
Malonyl coa
Phenylethamolamine N methyl transferase
Skin
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

37. What kind of branches do glycogen branches have
Flank pain - hematuria - HTN - progressive renal failure
Vit K antagonist
Epithelial cells
Alpha 1 -6 and alpha 1 -4

38. How does abetalipoproteinemia present and What is the defect
Wobble
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
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
Glycolysis and aerobic respiration

39. What is the RDE of glycogen synthesis
Modifies N- oligosaccharides
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Glycogen synthase

40. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
X linked frame shif mutation
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

41. 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
Cofactor for LPL
SNP
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

42. How do microtubules grow and collapse
Eu - methionine - pro - formyl - methionine
RNA
Grows slowly - collapses quickly
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS

43. Infection with what organism can cause B12 def
Diphyllobothrium latum
Dermatitis - alopecia - enteritis
Transfers methyl units
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

44. What is the RDE of TCA cycle
Glucose 6 phosphate dehydrogenase (G6PD)
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Isocitrate dehydrogenase
Sulfation

45. What does apoB100 do
Binds to LDL receptor - mediates VLDL secretion
No
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Adds 2 carbon with the help of biotin

46. What apolipoproteins are on chylomicrons
Cre - lox system
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
B48 - AIV - CII - E

47. protein malnutrition resulting in skin lesions - edema and liver malfxn
Kwashiorkor - small child with swollen belly
Dermatitis - alopecia - enteritis
Base + ribose
Wobble

48. What apolipoprotiens are on VLDL
B-100 - CII and E
High output cardiac failure - dilated cardiomyopathy - edema
Neurofibromatosis type 1 (von Recklinghausens disease)
Protein kinase A

49. Where are FADH2 electrons transferred to...
CarTWOlage
Comlex II
Histidine
Flank pain - hematuria - HTN - progressive renal failure

50. How does chloramphenicol work
IDL
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Inhibits 50S peptidyltransferase
Fructose 1 -6 bisphosphate