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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. Pts with albinism are at inc risk For what cancer
Skin
Phenytoin - MTX - and sulfonamides
Same as sprint + OXPHOS
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

2. deletion of VHL gene on chromosome 3 leading to hemangioblastomas of retina/cerebellum/medulla bilateral RCC - dz and overexpression product
Von hippel lindau - 3
Alpha 1 -4 glucosidase
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Alpha and beta tubulin - dimers have two GTP bound

3. What does the ELISA test for
SnRNPs
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Carbomoyl phosphate synthetase I
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

4. What can excess vit B3 cause
LCAT (lecithin cholesterol acyltransferase)
Facial flushing
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

5. How do microtubules grow and collapse
Grows slowly - collapses quickly
Alpha1 antitrypsin
Wobble
ADPKD

6. What does commaless - nonoverlapping genetic code refer to...
Locus heterogeneity - ocular albinism is x- linked recessive
Essential fructosuria - fructokinase AR
Read from a fixed starting point as a continuous sequence of bases
Phenylketones in urine

7. Which direction does kinesin go
Neg to pos
Disorder of aromatic amino acid metabolism
Seals.
Active secretion in lungs and GI - reabsorbs in skin

8. What does desmin stain for
Schilling test
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
Muscle
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

9. What does the start codon code for in eukaryotes and prokaryotes
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Eu - methionine - pro - formyl - methionine
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

10. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
DsRNA promotes degradation of target mRNA knocking down gene expression
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Huntingtons

11. recurrent pulmonary infxns in CF are due to what organisms
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Pseudomonas and s aureus
APC on chromosome 5
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

12. Type I collagen
Inhibit DNA gyrase specific for prokaryotic topoisomerase
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)
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Consesus sequenec of base pairs

13. How do permanent cells grow and regenerate and What are examples of permanent cells
B12 and folate
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Dermatitis - glossitis - and diarrhea

14. What defects characterize DiGeorge syndrome
Binds to LDL receptor - mediates VLDL secretion
CGG
Locus heterogeneity - ocular albinism is x- linked recessive
Thymic - parathyroid and cardiac

15. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
ATP
Inc melt - dec fluidity
Base + ribose
Schwann cells - lens - retina - kidneys

16. What are uncoupling agents
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
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Cofactor for LPL
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

17. What metabolic rxns occur in the cytoplasm
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Same AA - often base change in 3rd position of codon (tRNA wobble)
Degradation of TG stored in adipocytes
LDL

18. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Hereditary spherocytosis
Heterochromatin = HighlyCondensed
CGG

19. Which anti gout drugs work on microtubules
De novo pyrimidine synthesis and urea - ornithine transcarbamoyl def in the urea cycle leads to a build of CP - then converted to orotic acid in pyrimidine synthesis pathway
Colchicine
Carbomoyl phosphate synthetase I
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

20. What rxn creates ATP
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Carbomoyl phosphate synthetase I
Thymic - parathyroid and cardiac
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

21. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
BOne
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Essential fructosuria - fructokinase AR

22. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
CAG - 4
Intermediate filaments
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL

23. What are the results of unbalanced translocation
APKD1 on chromosome 16
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

24. What 3 syndromes are associated with vit B1 def
Ca/calmodulin in muscle to coordinate with muscle activity
GAA
Dermatitis - glossitis - and diarrhea
Wernicke - korsakoff - dry and wet beriberi

25. What does the golgi assemble proteoglycans from
EtOH dehydrogenase and acetaldehyde dehydrogenase
Phenylethamolamine N methyl transferase
Niacin - constituent of NAD and NADP - derived from tryptophan
Core proteins

26. What step of uric acid synthesis does xanthine oxidase catalyze
Oxidative is irreversible
Specific glycosylases - AP endonuclease
Hypoxanthine to xanthing and xanthine to uric acid
OTC has hyperammonemia - orotic aciduira does not

27. What are the only purely ketogenic amino acids
Lysine and leucine
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Actin and myosin
NADH - NADPH - FADH2

28. What does a phosphatase do
Removes phosphate group from substrate
CTG
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Phosphofructokinase 1

29. What are the blood glucose levels maintained by for days 1-3
Night blindness - dry skin
Keep glutathione reduced so it can detoxify free radicals and peroxides
Oxidative is irreversible
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)

30. What collagen type is most frequently affected in ehlers danlos and What are common complications
Reads usual codon but inserts wrong AA
Lysine and leucine
III - joint dislocation - anuerysms - organ rupture
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

31. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Transmitted only through mother - all offspring of affected females may show signs of disease
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
ADPKD

32. Where is EtOH dehydrogenase located
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Cytosol
Glycine

33. What 3 amino acids are necessary for purine synthesis
Glycine - aspartate - glutamine
Rb and p53
Elastase - inhibited by alpha1 antitrypsin
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

34. What is the activated carrier for methyl groups
APRT + PRPP
SAM
Transmitted only through mother - all offspring of affected females may show signs of disease
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

35. What is the defect in II A familial hypercholesterolemia
BOne
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Arginine

36. What is the Name and function of vit B1
Pyruvate to oxaloacetate (3C to 4C)
Glucose 6 phosphate dehydrogenase (G6PD)
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

37. What happens in hyperammonemia
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Glucose -6 phosphate
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

38. What is the defect in cystinuria
Glucose -6 phosphate
Cyclin dependent kinases;constitutive and inactive
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

39. inc glycogen in muscle but can't break it down - painful muscle cramps - myglobinuria with strenuous exercise - dz and enzyme
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
Mcardle's - skeletal muscle glycogen posphorylase
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
P+q = 1

40. What is locus heterogeneity and give an example
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Alpha - ketoglutarate dehydrogenase complex
Dec methionine - inc cystiene - inc B12/folate

41. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Kidney - ears - eyes
Infection - free radicals generated by inflammatory response
RNA poly II
DNA

42. What amino acid makes up most of the octamer
Lysine and arginine
Binds 50S - blocking translocation
TRNA
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

43. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Marfans
Glycine - aspartate - glutamine
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

44. What is the TX for PKU
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Seals.

45. How does ouabain work
Inhibits the Na/K pump by binding the K side
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

46. What does a carboxylase do
Debranching enzyme
ATP - citrate
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Adds 2 carbon with the help of biotin

47. What does Ehlers Danlos cause and why
Protein
Polyneuritis - symmetrical muscle wasting
Kwashiorkor - small child with swollen belly
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints

48. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
RNA poly II
Degredation of TG circulating in chylomicrons and VLDLs
Arg - lys - his - arg is most basic - has has no charge at body pH
X linked frame shif mutation

49. What is the RDE of gluconeogenesis
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Fructose 1 -6 bisphosphate
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

50. caf
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Neurofibromatosis type 1 (von Recklinghausens disease)
Glucose -6 phosphate
Connective tissue

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