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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. Type IV collagen is an important structural componenet of the BM for which 3 organs
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Cre - lox system
Kidney - ears - eyes
By inhibiting formation of the initiation complex and cause misreading of mRNA

2. What neuroanatomical strutures are injured in wernicke - korsakoff
Inc dicarboxylic acids - dec in glucose and ketones
Medial dorsal nucleus of thalamus - mamillary bodies
Inhibits the Na/K pump by binding the K side
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

3. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Same as sprint + OXPHOS
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Terminal regions - tropocollagen

4. Which direction does kinesin go
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Carbomoyl phosphate synthetase I
Neg to pos
HVA

5. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Base + ribose
Cre - lox system
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
X linked frame shif mutation

6. nucleotide repeat for fragile x
Nonsense > missense > silent
HMP shunt
Activates LCAT
CGG

7. Give an example of a mitochondrial inherited disease
Tryosine hydroxylase
Proton gradient
Peroxide
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

8. How does patients present with ADPKD
3' end (with CCA)
Abnormal protein folding - degradation before reaching cell surface
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Flank pain - hematuria - HTN - progressive renal failure

9. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

10. What substance inside the cell serves to oxidize glutatione
Peroxide
HMG- CoA (HMG- CoA to mevalonate
Tyrosine
Ribose 5- P to PRPP

11. What is the order of severity for the different types of mutations
Malapsorption syndromes like sprue or CF or mineral oil intake
Nonsense > missense > silent
Peroxide
Met - val - arg his

12. What tissues have both enzymes of sorbitol metabolism
Liver - ovaries - seminal vesicles
Ca/calmodulin in muscle to coordinate with muscle activity
Schilling test
Deamination

13. Where do you find elastin and What does it do
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
No - its non homologous
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Collagen

14. What is the breakdown product of epi
African Americans and Asians
Metanephrine
Krabbes - galactocerebrosidase - galactocerebroside - AR
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

15. 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
Activates LCAT
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Hereditary spherocytosis

16. What shuttle is involved in fatty acid synthesis and What does it move From where to where
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Citrate - acetyl coa from mito to cyto

17. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Must be both activated and inactivated for cell cycle to progress
Neg to pos
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
IDL

18. What metabolic rxns occur in both the cytoplasm and mitochondria
NAD+
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA

19. What does hartnups disease cause
Mediates chylomicron secretion
Breaks down acyl - coa to acetyl coa groups in mito
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

20. What does commaless - nonoverlapping genetic code refer to...
Read from a fixed starting point as a continuous sequence of bases
Protein kinase A
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

21. What is the amino acid precursor for catecholamines
Phenylketones in urine
MEN - 2A and 2B with ret gene
Phenylalanine
Lacks glucose 6 phophatase

22. What does a defective Cl channel do
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
CarTWOlage
Microarrays
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

23. characterize autosomal recessive inheritance
Glycogen phosphorylase
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
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Bind 30s subunit preventing attachment of aminoacyl - tRNA

24. What is the RDE of fatty acid oxidation
Carnitine acyltransferase I
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
No

25. bilateral - massive enlargement of of kidneys due to multiple large cysts
Oligomycin
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Marasmus - muscle wasting
ADPKD

26. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Griseofulvin
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Dopa decarboxylase
Chylomicrons

27. What happens in vit B2 def
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Ribose 5- P to PRPP
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex

28. What does a kinase do
CAG - 4
Uses ATP to add high energy phophate group onto substrate
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
17 - 17 letters in von Recklinghausen

29. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Ribose 5- P to PRPP
Schilling test
III - joint dislocation - anuerysms - organ rupture
Comlex II

30. What happens with wet beriberi
In ER - glucose 6- P to glucose
G6PD
Consesus sequenec of base pairs
High output cardiac failure - dilated cardiomyopathy - edema

31. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Comlex II
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Nonsense > missense > silent

32. What is I cell disease
Fasting
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Glucose 6 phosphate dehydrogenase (G6PD)

33. what disease can cause pellagra
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Phenytoin - MTX - and sulfonamides
Basement membrane or basal lamina

34. What liberates glucose from glucose 6 P
Oral uridine administration
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Glucose 6 phosphatase
Polyneuritis - symmetrical muscle wasting

35. What enzyme def can cause emphysema
Alpha1 antitrypsin
Terminal regions - tropocollagen
Nature and severity of phenotype vary from 1 individual to another - NF type 1
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)

36. How many rings do pyrimidines have
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Achondroplasia
1 ring
Wernicke - korsakoff - dry and wet beriberi

37. Adenosine deaminase deficiency is an important cause of what immunodeficiency?
40 - 60 - 80
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
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Dec DNA - dec lymphos leads to SCID

38. What enzyme does fructose metabolism bypass to reach glycolysis
CAG - 4
Tryosine hydroxylase
PFK - rate limiting enzyme
Liver - also in kidney and gut epithelium

39. What is the Name and fxn of vit B5
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Adds an inorganic phosphate onto substrate without using ATP
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Removal of N or C termal propeptides from zymogens to generate mature proteins

40. delivers hepatic TGs to peripheral tissue - secreted by liver
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
VLDL
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Histidine

41. What is dominant negative mutation and give an example
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
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

42. What are the purely ketogenic amino acids
Leu - lys
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Post to neg
Proline and lysine - vit C

43. What can vit B3 be used to treat
Adenosine to inosine
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Hyperlipidemia

44. What are the symptoms of vit A def
CAG - 4
Night blindness - dry skin
RNA poly II
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate

45. Which direction does dynein go
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Post to neg
Carnitine shuttle - acyl - coa from cyto to mito

46. What is the Hardy Weinberg disease prevalence equation
Ribose 5- P to PRPP
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
P2 +2pq+ = 1

47. How does abetalipoproteinemia present and What is the defect
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
Glycine
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

48. What ribosomes do prokaryotes have
Wernicke - korsakoff - dry and wet beriberi
Night blindness - dry skin
30 - 50 - 70
Scrutinizes - hydrolyzes the bond

49. Which end of the tRNA is the amino acid bound to...

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50. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Carbomoyl phosphate synthetase I
Inc insulin - dec cAMP - dec PKA
Alpha - ketoglutarate dehydrogenase complex
L form