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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. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
CarTWOlage
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Post to neg
Promotor - TATA box - and CAAT box - AT rich

2. protein malnutrition resulting in skin lesions - edema and liver malfxn
Kwashiorkor - small child with swollen belly
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Krabbes - galactocerebrosidase - galactocerebroside - AR
No

3. What defects characterize velocardiofacial syndrome
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Palate - facial and cardiac defects
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Glycolysis and aerobic respiration

4. Why can't even chain fatty acids produce new glucose
Inhibit DNA gyrase specific for prokaryotic topoisomerase
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
They yield only acetyl - CoA equivalents
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates

5. What is the Hardy Weinberg disease prevalence equation
B48 - AIV - CII - E
Removal of N or C termal propeptides from zymogens to generate mature proteins
P2 +2pq+ = 1
Degredation of dietary TG in small intestine

6. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
P2 +2pq+ = 1
Result from phagocytic removal of heinz bodies my macs - G6PD def

7. What converts limit dextran to glucose
Debranching enzyme
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

8. Which aspect of the spliceosome do patients with lupus make antibodies against
HMG- CoA (HMG- CoA to mevalonate
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Terminal regions - tropocollagen
SnRNPs

9. What does beta oxidation do and Where does it occur
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
Ribos first then deoxyribos with ribonucleotide reductase
Initiate chains
Breaks down acyl - coa to acetyl coa groups in mito

10. What are the findings in orotic aciduria
Protein kinase A
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Alpha - ketoglutarate dehydrogenase complex
APKD1 on chromosome 16

11. What inhibits pyruvate kinase
ATP and alanine
Must be both activated and inactivated for cell cycle to progress
Initiate chains
Proline and lysine - vit C

12. what disease can cause pellagra
Orotate precursor - with PRPP added later
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Degradation of TG stored in adipocytes
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

13. How many rings do pyrimidines have
Neither of 2 alleles is dominant - blood groups
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
B48 - AIV - CII - E
1 ring

14. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Enhancers
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

15. What are the characteristics of angelmans syndrome and How does it occur
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Colchicine
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

16. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Locus heterogeneity - ocular albinism is x- linked recessive
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

17. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Autosomal recessive diseases
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
CAG - 4

18. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
RER
Anchor muscle fibers - primarily in skeletal and cardiac muscle
30 - glycerol -3- phosphate shuttle

19. What is the results of vit B1 def
Alpha - ketoglutarate dehydrogenase complex
Cleft palate - cardiac abnl - pregs test
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

20. What causes B12 def
2 rings
Glycogen phosphorylase
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns

21. What are ketone bodies made from - where are they metabolized and how are they excreted
Inc dicarboxylic acids - dec in glucose and ketones
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Autosomal recessive diseases

22. 90% of ADPKD cases are due to a mutation In what gene
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
Glucose - 2Pi - 2ADP - 2NAD+
Glycogenolysis to form glucose
APKD1 on chromosome 16

23. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Von gierkes - glucose 6 phosphatase
Terminal regions - tropocollagen
Read from a fixed starting point as a continuous sequence of bases
Vit K antagonist

24. What does a mischarge tRNA do
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Uses ATP to add high energy phophate group onto substrate
Inhibits 50S peptidyltransferase
Reads usual codon but inserts wrong AA

25. trinucleotide repeat for huntingtons
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
More than 1 codon may code for the same amino acid
CAG
HGPRT - defective purine salvage - excess uric acid production

26. What can vit B3 be used to treat
Proline and lysine - vit C
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Hyperlipidemia
Carbomoyl phosphate synthetase I

27. What enzyme does fructose metabolism bypass to reach glycolysis
Orotic acid to UMP
PFK - rate limiting enzyme
Deamination
Covalent cross - linking by lysyl oxidase to make collagen fibrils

28. Which anti gout drugs work on microtubules
75 to 90 - cloverleaf
Autosomal recessive diseases
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Colchicine

29. What is the prevalence of an X- linked recessive disease in males and in females
Skin
Carnitine shuttle - acyl - coa from cyto to mito
Von hippel lindau - 3
Q -

30. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Familial hypercholesterolemia - hyperlipidemia type IIA
X- linked recessive
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

31. What is made fir rNucleotides or deoxyrNucleotides and what enzyme is necessary to convert one to the next
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
FAP
Ribos first then deoxyribos with ribonucleotide reductase

32. What apolipoproteins are on chylomicrons
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
B48 - AIV - CII - E
Metanephrine
III - joint dislocation - anuerysms - organ rupture

33. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Glucose 6 phosphatase
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Inc insulin - dec cAMP - dec PKA
DNA

34. What is the Name and function of vit B2
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Degradation of TG stored in adipocytes
After day 1
Lacks glucose 6 phophatase

35. What is codominance and give an example
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Liver - ovaries - seminal vesicles
Neither of 2 alleles is dominant - blood groups
B100

36. Which enzyme involved in RNA synthesis does not require a template
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Liver hepatocytes and steroid producing cells of the adrenal cortex
Creat a nick in the helix to relieave supercoils created during replication
Poly A polymerase - signal is AAUAA

37. How do tetracyclines work
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Asp and Glu
Bind 30s subunit preventing attachment of aminoacyl - tRNA
No

38. What does pancreatic lipase do
Degredation of dietary TG in small intestine
Connective tissue
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
CGG

39. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Infection - free radicals generated by inflammatory response
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

40. What is the amino acid precuros for niacin and serotonin/melatonin
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Tryptophan
Initiate chains
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

41. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Oxalacetate
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Unmethylated - newly synthesized - HNPCC
Inc melt - dec fluidity

42. What is proteasomal degredation
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Attachment of ubiquitin to defective proteins tag them for breakdown
Specific glycosylases - AP endonuclease

43. What does an umabiguous genetic code refer to...
MEN - 2A and 2B with ret gene
Two
Sucrose = glucose + fructose - lactose = glucose + galactose
Each codon specifies only 1 amino acid

44. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Binds to LDL receptor - mediates VLDL secretion
Marfans
Vincritsine/vinblastine
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

45. How are the many staggered tropocollagen molecules reinforced
Neuralgia
Covalent cross - linking by lysyl oxidase to make collagen fibrils
ATP
Wobble

46. What is the RDE of cholesterol synthesis
Superoxide dismutase
HMG- CoA reductase
Achondroplasia
Glycolysis and aerobic respiration

47. Which cells are rich in smooth ER
Liver hepatocytes and steroid producing cells of the adrenal cortex
Malapsorption syndromes like sprue or CF or mineral oil intake
Site of steroid synthesis and detoxification of drugs and poisons
Basement membrane or basal lamina

48. How is ammonium transported from muscle to the liver for urea cycle
Lysine and leucine
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
HGPRT - defective purine salvage - excess uric acid production
DsRNA promotes degradation of target mRNA knocking down gene expression

49. What substances inhibit phosphofructokinase -1
ATP - citrate
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Cri du chat
Cartilage - hyaline - vitreous body - nucleus pulposus

50. Type IV BM
4 under the floor
High output cardiac failure - dilated cardiomyopathy - edema
Polycystic liver disease - berry aneurysm - mitral valve prolapse
After day 1