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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. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
X linked frame shif mutation
CGG
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Marfans

2. What is mosaicism and give an example
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)
RER
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
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond

3. How do macrolides and clindamycin work
B48 - AIV - CII - E
Binds 50S - blocking translocation
Neural tube
Elastase - inhibited by alpha1 antitrypsin

4. What causes B12 def
Metanephrine
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Protein kinase A

5. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Seals.
Euchromatin
Conversion of NE to epi

6. What are the functinos of vitamin A
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Antibiotic use or excessive ingestion of raw eggs
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

7. When are glycogen reserves depleted
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
N to C
After day 1
TRNA

8. What is the energy source after day 3 of starvation
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
ATP
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
IMP precursor

9. Do balanced translocations cause abnl phenotype
SAM
No
Procollagen - triple helix of 3 alpha collagen chains
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

10. What is a nonsense mutation
Silencers
Arg and his inc in histones Which bind negatively charged DNA
Locus heterogeneity - ocular albinism is x- linked recessive
Change resulting in early stop codon

11. What is the activated carrier for electrons
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Breaks down acyl - coa to acetyl coa groups in mito
NADH - NADPH - FADH2
Inc dicarboxylic acids - dec in glucose and ketones

12. 1 g of protein or cabrohydrate = ?kcal
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Four
Cofactor for LPL

13. What causes maple syrup urine disease and What does it lead to...
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
Unmethylated - newly synthesized - HNPCC
RRNA
Result from phagocytic removal of heinz bodies my macs - G6PD def

14. What rxn does propionyl - CoA carboxylase catalyze
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Acetyl - CoA carboxylase (ACC)
Microtubules

15. What enzyme converts phenylalanine to tyrosin
Semiconservative - continuous and discontinuous strands (okazaki fragments)
HDL
Phenylalanine hydroxylase
75 to 90 - cloverleaf

16. What does an umabiguous genetic code refer to...
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Each codon specifies only 1 amino acid
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
17 - 17 letters in von Recklinghausen

17. Where is PEP carboxykinase found - What does it do - and What does it require
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Modifies N- oligosaccharides
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
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

18. What metabolic rxns occur in the mitochondria
Cleft palate - cardiac abnl - pregs test
Muscle
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Hereditary spherocytosis

19. In base excision repaire - what recognizes and removes damaged bases and what cuts the DNA to remove the empty sugar
Phosphofructokinase 1
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Essential fructosuria - fructokinase AR
Specific glycosylases - AP endonuclease

20. What kind of branches do glycogen branches have
Alpha 1 -6 and alpha 1 -4
EtOH dehydrogenase and acetaldehyde dehydrogenase
Thymic - parathyroid and cardiac
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

21. What liberates glucose from glucose 6 P
Tyrosine
Intermediate filaments
Not all individuals with a mutant genotype show the mutant phenotype
Glucose 6 phosphatase

22. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Rotenone - CN- - antimycin A - CO
Basement membrane or basal lamina
LDL
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

23. What is maternal PKU
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
L form
Creat a nick in the helix to relieave supercoils created during replication

24. What are the fetal screening measures for Down
Flank pain - hematuria - HTN - progressive renal failure
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
PCR - denaturation - annealing - elongation
Transfers methyl units

25. I g fat = ? Kcal
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
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Nine
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

26. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
PCR - denaturation - annealing - elongation
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Alpha1 antitrypsin

27. In eukaryotes - What does RNA poly III make
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Inc Cl - in sweat
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
TRNA

28. What clotting factors require vit K
Malonyl coa
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
II - VII - IX - X (1972) protein C and S
Infection - free radicals generated by inflammatory response

29. Why is G6PD def more common among patients of african decent
Protective against malaria
Nissl body - enzyme and NTs
Fibrofatty replacement of muscle - cardiac myopathy
No

30. What is the physiologic role of dystrophin
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Myeloperoxidase
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels

31. What does glycosylation of pro alpha chian yield and What is the structure
Inc melt - dec fluidity
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
APKD1 on chromosome 16
Procollagen - triple helix of 3 alpha collagen chains

32. What do the single stranded binding proteins do
AR
Prevent strands from reannealing
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

33. What are CDKs
Diphyllobothrium latum
Four
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Cyclin dependent kinases;constitutive and inactive

34. What are the reactants for glycolysis
Liver - also in kidney and gut epithelium
Disorder of aromatic amino acid metabolism
Glucose - 2Pi - 2ADP - 2NAD+
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

35. What does DNA poly III do?

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36. What are the results of pancreatic insuff in CF
Poly A polymerase - signal is AAUAA
Malabsorption and steatorrhea (ADEK)
RRNA
Alpha - ketoglutarate dehydrogenase complex

37. ADPKD is associated with What additional conditions
GTP
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Lysine and leucine
Medial dorsal nucleus of thalamus - mamillary bodies

38. What are the fat soluble vitamins and What does their absorption depend on...
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Hypoxanthine to xanthing and xanthine to uric acid

39. What substance inside the cells replenishes NADPH
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
TTP
G6PD
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

40. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Mucus secreting globlet cells and antibody secreting plasma cells
Targets the proteins for lysosome
Site of steroid synthesis and detoxification of drugs and poisons
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

41. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
BOne
Locus heterogeneity - ocular albinism is x- linked recessive
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
MEN - 2A and 2B with ret gene

42. cytoskeletal elements associated with vimenentin - desmin - cytokeratin - glial fibrillary acid protiens (GFAP) - neurofilaments
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Procollagen - triple helix of 3 alpha collagen chains
Intermediate filaments

43. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
Lysine and arginine
LDL
ATP hyrdolysis couple to energetically unfavorable rxns
HGPRT - defective purine salvage - excess uric acid production

44. Patients with chronic granulomatous disease are at increased risk of infection From which kind of organisms
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Microarrays
Base + ribose + phosphate (3' -5') phosphodiester bond
Y shaped region along the DNA template where leading nad lagging strands are synthesized

45. What does desmin stain for
Muscle
Krabbes - galactocerebrosidase - galactocerebroside - AR
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Arginine

46. What does the mutation in the gene cause in protein synthesis
Abnormal protein folding - degradation before reaching cell surface
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Two
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

47. What does biotin def cause
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Transfers methyl units
Dermatitis - alopecia - enteritis
Nonsense > missense > silent

48. How do you diagnose CFTR
Inc Cl - in sweat
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Disorder of aromatic amino acid metabolism
II - VII - IX - X (1972) protein C and S

49. What is the smallest mutation a mircoarray can detect
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Inc melt - dec fluidity
SNP
Sulfation

50. What does a northern blot use as its sample
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
RNA
Familial hypercholesterolemia - hyperlipidemia type IIA
VMA