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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 is the energy source for translocation
GTP
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Transfers methyl units
NADH - NADPH - FADH2

2. What enzyme converts phenylalanine to tyrosin
Four
CGG
LCAT (lecithin cholesterol acyltransferase)
Phenylalanine hydroxylase

3. What is the amino acid precuror for creatine - urea and nitric oxide
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Arginine
Failure to track objects or develop a social smile
Muscle

4. What is incomplete penetrence and give an example
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Not all individuals with a mutant genotype show the mutant phenotype
NAD+
Binds to LDL receptor - mediates VLDL secretion

5. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
Semiconservative - continuous and discontinuous strands (okazaki fragments)
RER
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Acetoacetate and beta hydroxybutyrate

6. characterize autosomal recessive inheritance
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
Type II
X linked frame shif mutation
Actin and myosin

7. What is the energy source after day 3 of starvation
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
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
Inc dicarboxylic acids - dec in glucose and ketones

8. What happens in vit K def
Von Gierke's - Pompe - Cori - McArdle
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Phenylalanine hydroxylase

9. What is the fxn of vit K
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Creat a nick in the helix to relieave supercoils created during replication

10. Which anti gout drugs work on microtubules
IDL
Colchicine
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
5' of the incoming nucleotide

11. What is the breakdown product of epi
Metanephrine
L form
Scrutinizes - hydrolyzes the bond
Specific glycosylases - AP endonuclease

12. caf
B-100 - CII and E
Neurofibromatosis type 1 (von Recklinghausens disease)
IMP precursor
RER

13. This is the site where negative regulators bind
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Silencers
Inc vit B6
ATP and methionine

14. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
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
CAG - 4
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

15. Describe the location and fxn of the Na/K ATPase
30 - glycerol -3- phosphate shuttle
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Phenylalanine hydroxylase
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

16. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
32 - malate aspartate shuttle
Liver - ovaries - seminal vesicles
Proline and lysine - vit C
Hypoxanthine to xanthing and xanthine to uric acid

17. 90% of ADPKD cases are due to a mutation In what gene
APKD1 on chromosome 16
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Euchromatin

18. What kind of RNA is transported out of the nucleus
Basement membrane or basal lamina
X- linked recessive
Only processed RNA
Ribose 5- P to PRPP

19. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
1 ring
Familial hypercholesterolemia - hyperlipidemia type IIA
Read from a fixed starting point as a continuous sequence of bases

20. What CETP do
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
HMG- CoA reductase
CarTWOlage

21. What are the characteristics of prader willi syndrome How does it occur
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
DNA
They yield only acetyl - CoA equivalents
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

22. What happens in a B12 def
Alanine
APC on chromosome 5
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

23. What do DNA topoisomerases do
Creat a nick in the helix to relieave supercoils created during replication
Oxidative is irreversible
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

24. What happens do glycogen in skeletal muscle during exercise
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Glycogenolysis to form glucose
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Defect in fibrillin

25. What causes Down syndrome
Not all individuals with a mutant genotype show the mutant phenotype
5' of the incoming nucleotide
Isocitrate dehydrogenase
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

26. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
1 ring
MEN - 2A and 2B with ret gene
Acetyl - CoA carboxylase (ACC)
Phosphofructokinase 1

27. What happens in elongation of protein synthesis

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28. Mediates reverse cholesterol transport from periphery to liver - acts as respository for apoC an apoE - secreted from both liver and small intestine
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
HDL
HGPRT - defective purine salvage - excess uric acid production
FISH

29. What are Heinz bodies
4 under the floor
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Oxidized hemoglobin precipiated within RBCs

30. What ribosomes do eukaryotes have
NF2 on chromosome 22
40 - 60 - 80
Conversion of NE to epi
Orotate precursor - with PRPP added later

31. Name as many x- linked recessive disorders as you can

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32. What are the 4 assumption of the Hardy Weinberg law
PCR - denaturation - annealing - elongation
Base + ribose + phosphate (3' -5') phosphodiester bond
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Inc insulin - dec cAMP - dec PKA

33. What does a phosphatase do
Malapsorption syndromes like sprue or CF or mineral oil intake
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Removes phosphate group from substrate
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

34. What is the active form of vit D
1 -25 OH2 D3 = calcitriol
Adds 2 carbon with the help of biotin
THFs
Glucose -6 phosphate

35. What does DNA poly I do?
Blood - bone marrown - amniotic fluid - placental tissue
Uses ATP to add high energy phophate group onto substrate
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

36. trinucleotide repeat for huntingtons
O- oligosaccharaides
Glutamine PRPP amidotransferase
CAG
Glycine - aspartate - glutamine

37. What are the results of pancreatic insuff in CF
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Malabsorption and steatorrhea (ADEK)
Disorder of aromatic amino acid metabolism
AMP - fructose 2 -6 BP

38. 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
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Intermediate filaments
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

39. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Alanine
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Same AA - often base change in 3rd position of codon (tRNA wobble)
9+2 arrangement of microtubules

40. What induces pyruvate kinase
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
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
F16BP
Collagen

41. What is the function of Zinc
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Nine
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Mutated dystrophin gene - less severe - adolescence

42. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Fibrofatty replacement of muscle - cardiac myopathy
Oxidized hemoglobin precipiated within RBCs
DsRNA promotes degradation of target mRNA knocking down gene expression
Peroxide

43. What does a dehydrogenase do
Enhancers
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Only processed RNA
Oxidizes substrate

44. What does commaless - nonoverlapping genetic code refer to...
MRNA - tRNA
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Read from a fixed starting point as a continuous sequence of bases
CGG

45. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Marfans
Glucose 6 phosphatase
Alpha1 antitrypsin
Tropoelastin with fibrillin scafolding

46. What does vit E def cause
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

47. What metabolic rxns occur in both the cytoplasm and mitochondria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Carbomoyl phosphate synthetase II
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
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

48. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
Mucus secreting globlet cells and antibody secreting plasma cells
CG- 3 > AT-2 - More CG content - melting point goes up
Hyperlipidemia
Achondroplasia

49. Where is acetaldehyde located
Mitochondria
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Keep glutathione reduced so it can detoxify free radicals and peroxides
Transfers methyl units

50. What is the limiting reagent in EtOH metabolism
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
NAD+
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Histidine