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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. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Transfers methyl units
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Ketone - methyl

2. What does fomepizole do
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
B-100 - CII and E
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
AMP - fructose 2 -6 BP

3. What does vit E def cause
Epithelial cells
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

4. What does DNA poly I do?
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
CG- 3 > AT-2 - More CG content - melting point goes up
HMG- CoA synthase
Arg - lys - his - arg is most basic - has has no charge at body pH

5. What are pyrimidines made from
Palate - facial and cardiac defects
Orotate precursor - with PRPP added later
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Cytosol - F 1 -6 BP to fructose 6 Phosphate

6. How do aminoglycosides work
B6
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
By inhibiting formation of the initiation complex and cause misreading of mRNA

7. What is the breakdown product of dopamine
Hereditary spherocytosis
Poly A polymerase - signal is AAUAA
Euchromatin
HVA

8. What are the findings in PKU
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Adenosine to inosine
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
Actin and myosin

9. How does chloramphenicol work
BOne
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Inhibits 50S peptidyltransferase
SNP

10. What is the longest time of RNA and shortest
3' end (with CCA)
CarTWOlage
Carbomoyl phosphate synthetase I
MRNA - tRNA

11. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Oral uridine administration
40 - 60 - 80
Glycogen synthase

12. What enzyme def can cause emphysema
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Hypoxanthine to xanthing and xanthine to uric acid
Alpha1 antitrypsin
Seals.

13. What is disulfiram used for
B100 and E
Acetyl - CoA to malonyl - CoA (2C to 3C)
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Ribos first then deoxyribos with ribonucleotide reductase

14. What is the Name and fxn of vit B12
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
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
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

15. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
2 rings
Wrinkles and acne
PCR - denaturation - annealing - elongation

16. What clotting factors require vit K
ADPKD
Arg and his inc in histones Which bind negatively charged DNA
II - VII - IX - X (1972) protein C and S
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

17. What are purines made from
NAD+
Pseudomonas and s aureus
IMP precursor
Acetyl - CoA

18. How do macrolides and clindamycin work
CAG - 4
Myeloperoxidase
Binds 50S - blocking translocation
Changed AA (convservative - new AA is similar in chemical structure)

19. What defects characterize DiGeorge syndrome
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Thymic - parathyroid and cardiac

20. What does apoA 1 do
Activates LCAT
Oligomycin
Post to neg
Cre - lox system

21. The pyruvate dehydrogenase complex serves In what reaction: products
Acetly- CoA - CO2 - NADH
Hypoxanthine to xanthing and xanthine to uric acid
B12 and folate
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

22. What enzyme turns ROS to H2O2
Superoxide dismutase
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
AR
EtOH dehydrogenase and acetaldehyde dehydrogenase

23. What is the RDE of gluconeogenesis
3' end (with CCA)
ATP - citrate
LCAT (lecithin cholesterol acyltransferase)
Fructose 1 -6 bisphosphate

24. What are the 4 assumption of the Hardy Weinberg law
CarTWOlage
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Poly A polymerase - signal is AAUAA
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

25. What are the function of vit C
Transfers methyl units
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
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Breaks down acyl - coa to acetyl coa groups in mito

26. What are Heinz bodies
Tyrosine
Oligomycin
Oxidized hemoglobin precipiated within RBCs
Only processed RNA

27. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Dopamine beta hydroxylase
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
OTC has hyperammonemia - orotic aciduira does not

28. Which direction does kinesin go
Neg to pos
5' of the incoming nucleotide
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
9+2 arrangement of microtubules

29. What does universal genetic code refer to and What are some exception
APRT + PRPP
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
IMP precursor
III - joint dislocation - anuerysms - organ rupture

30. What are cyclins
AR
Cleft palate - cardiac abnl - pregs test
Facial flushing
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

31. What two amino acids are required druing periods of growth and why
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
TTP
Arg and his inc in histones Which bind negatively charged DNA

32. what disease can cause pellagra
4 under the floor
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Degredation of TG circulating in chylomicrons and VLDLs
Proline and glycine (non glycosylated forms)

33. What is the most common urea cycle disorder and What is the mode of inheritance?
Grows slowly - collapses quickly
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
FMR1 gene - methylation - associated with chromosomal breakage

34. What does a southern blot use as its sample
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
DNA
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
Malonyl coa

35. What does biotin def cause
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Dermatitis - alopecia - enteritis
Fed
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

36. What does CATCH 22 stand for and What causes is...
B12 and folate
Nonsense > missense > silent
Oligomycin
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

37. What does apoB48 do
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Mediates chylomicron secretion
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Degredation of dietary TG in small intestine

38. What converts DOPA to dopamine
Carbomoyl phosphate synthetase I
Dopa decarboxylase
HVA
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

39. 1 g of protein or cabrohydrate = ?kcal
Four
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
NADPH

40. What are the purely ketogenic amino acids
Transmitted only through mother - all offspring of affected females may show signs of disease
HGPRT - defective purine salvage - excess uric acid production
Autosomal recessive diseases
Leu - lys

41. How many rings do pyrimidines have
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Tuberous sclerosis
1 ring
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

42. What induces pyruvate kinase
Diphyllobothrium latum
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
F16BP
Seals.

43. What is the RDE of fatty acid oxidation
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
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
EtOH dehydrogenase and acetaldehyde dehydrogenase
Carnitine acyltransferase I

44. How does ethanol induce hypoglycemia
Adds 2 carbon with the help of biotin
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Alpha 1 -4 glucosidase
Heterochromatin = HighlyCondensed

45. inc glycogen in muscle but can't break it down - painful muscle cramps - myglobinuria with strenuous exercise - dz and enzyme

46. What is the activated carrier for methyl groups
SAM
CFTR gene - 7 - Phe 508
ATP
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism

47. What does Alports syndrome cause and why
RNA poly II
Vincritsine/vinblastine
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

48. What causes Edwards syndrome and What is it
Trisomy 18 - severe mental retardation - rocker bottom feet - micrognathia - low set ears - clenched hands - prominent occiput - congenital heart disease - death usually within the first year
Inc glucagon - inc cAMP - inc PKA
Microtubules
DsRNA promotes degradation of target mRNA knocking down gene expression

49. Why can't even chain fatty acids produce new glucose
EtOH dehydrogenase and acetaldehyde dehydrogenase
They yield only acetyl - CoA equivalents
Robertsonian translocation and mosaicism
Neg to pos

50. What are the symptoms of vit A excess
Ile - phe - thr - trp
Antioxidant - protects RBCs and membrances from free radical damage
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Post to neg