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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What co - factors are required for the pyruvated dehydrogenase complex
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Fibrofatty replacement of muscle - cardiac myopathy
Exercise: inc NAD/NADH - inc ADP - inc Ca
EtOH dehydrogenase and acetaldehyde dehydrogenase

2. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Tryosine hydroxylase
Schilling test
Von gierkes - glucose 6 phosphatase

3. What does DNA ligase do
Seals.
Lysine and leucine
CFTR gene - 7 - Phe 508
Skin

4. What is the RDE of the urea cycle
Dermatitis - alopecia - enteritis
Robertsonian translocation and mosaicism
NF2 on chromosome 22
Carbomoyl phosphate synthetase I

5. What does a phosphorylase do
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Arginine
3' end (with CCA)
Adds an inorganic phosphate onto substrate without using ATP

6. What induces pyruvate kinase
GTP
Tropoelastin with fibrillin scafolding
F16BP
Pseudomonas and s aureus

7. What are the two possible causes of albinism
Prevent strands from reannealing
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

8. nucleotide repeat for fragile x
Silencers
Mediates extra remnant take up
CGG
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

9. How do aminoglycosides work
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
By inhibiting formation of the initiation complex and cause misreading of mRNA
Alpha 1 -6 and alpha 1 -4
OTC has hyperammonemia - orotic aciduira does not

10. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Glycine - aspartate - glutamine
Rotenone - CN- - antimycin A - CO
Oxalacetate
Familial hypercholesterolemia - hyperlipidemia type IIA

11. Which enzyme involved in RNA synthesis does not require a template
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Poly A polymerase - signal is AAUAA
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Liver - also in kidney and gut epithelium

12. How do tetracyclines work
Active secretion in lungs and GI - reabsorbs in skin
No - its non homologous
Inhibits RNA polymerase II - found in death cap mushrooms
Bind 30s subunit preventing attachment of aminoacyl - tRNA

13. How does cytosine become uracil
Krabbes - galactocerebrosidase - galactocerebroside - AR
HMP shunt
Deamination
Foliage - small reserve in liver - eat green leaves

14. what gene is implicated in fragile X syndrome - and What is the mutation
Skin
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Dec DNA - dec lymphos leads to SCID
FMR1 gene - methylation - associated with chromosomal breakage

15. What is a silent mutation
Robertsonian translocation and mosaicism
Failure to track objects or develop a social smile
Disorder of aromatic amino acid metabolism
Same AA - often base change in 3rd position of codon (tRNA wobble)

16. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
N to C
Alpha - ketoglutarate dehydrogenase complex
Microarrays
VMA

17. characterize x linked recessive
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
Poly A polymerase - signal is AAUAA
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Alpha 1 -6 and alpha 1 -4

18. What else can phosphoylate phosphorylase kinase
Histidine
Actin and myosin
Ca/calmodulin in muscle to coordinate with muscle activity
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

19. Do balanced translocations cause abnl phenotype
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Same as sprint + OXPHOS
No
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

20. What happens with wet beriberi
High output cardiac failure - dilated cardiomyopathy - edema
Diphyllobothrium latum
Mediates extra remnant take up
Alpha1 antitrypsin

21. How is ammonium transported from muscle to the liver for urea cycle
Glycogen synthase
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
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Carnitine shuttle - acyl - coa from cyto to mito

22. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
CAG - 4

23. What are the clinical features of I cell diesase
Anabolic processes as a supply of reducing equivalents
30 - 50 - 70
Leu - lys
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

24. What kind of RNA is transported out of the nucleus
Only processed RNA
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
17 - 17 letters in von Recklinghausen

25. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
40 - 60 - 80
Huntingtons
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

26. What are the results of pancreatic insuff in CF
DTMP
Degredation of TG circulating in chylomicrons and VLDLs
Malabsorption and steatorrhea (ADEK)
CarTWOlage

27. What does the vimentin stain for
Nine
Particular sequence of DNA where replicatino begins - may be single of multiple
Connective tissue
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

28. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Mediates chylomicron secretion
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Heterochromatin = HighlyCondensed
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet

29. What does a southern blot use as its sample
DNA
III - joint dislocation - anuerysms - organ rupture
Lariat shape in order and remove intron precisely and join 2 exons
Pyruvate to oxaloacetate (3C to 4C)

30. What step of uric acid synthesis does xanthine oxidase catalyze
Hypoxanthine to xanthing and xanthine to uric acid
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Elastase - inhibited by alpha1 antitrypsin
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia

31. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Mebendazole/thiabendazole
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

32. What is the RDE of de novo purine synthesis
30 - 50 - 70
ADPKD
HMG- CoA synthase
Glutamine PRPP amidotransferase

33. What is the structure of elastin
Enhancers
Tropoelastin with fibrillin scafolding
LCAT (lecithin cholesterol acyltransferase)
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

34. In prokaryotes - What does makes the different types of RNA
Robertsonian translocation and mosaicism
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
1 kind with multiple subunits

35. How does insulin inhibit glycogenolysis
Keep glutathione reduced so it can detoxify free radicals and peroxides
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
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Microarrays

36. When are glycogen reserves depleted
After day 1
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
PCR - denaturation - annealing - elongation
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

37. What enzyme converts glucose 1 p to UDP glucose
Acetyl - CoA
UDP glucose pyrophosphorylase
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
P2 +2pq+ = 1

38. What causes Marfan syndrome
Defect in fibrillin
17 - 17 letters in von Recklinghausen
Enhancers
Removal of N or C termal propeptides from zymogens to generate mature proteins

39. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
RER
Glucose 6 phosphatase
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
Semiconservative - continuous and discontinuous strands (okazaki fragments)

40. What does apoB48 do
25OHD3
Mediates chylomicron secretion
Wrinkles and acne
Oligomycin

41. What are purines made from
IMP precursor
DTMP
Site of steroid synthesis and detoxification of drugs and poisons
Protein kinase A

42. What does commaless - nonoverlapping genetic code refer to...
Neg to pos
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Read from a fixed starting point as a continuous sequence of bases
Activates LCAT

43. Which anti gout drugs work on microtubules
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Colchicine
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Night blindness - dry skin

44. Why enzyme breaks down elastin and what enzyme inhibits it
Elastase - inhibited by alpha1 antitrypsin
Cytosol
Transmitted only through mother - all offspring of affected females may show signs of disease
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

45. What does vit C def cause
Degredation of dietary TG in small intestine
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
High output cardiac failure - dilated cardiomyopathy - edema
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response

46. What does the golgi apparatus do on asparagine
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
CFTR gene - 7 - Phe 508
Modifies N- oligosaccharides
RER

47. What does a northern blot use as its sample
RNA
Oxidized hemoglobin precipiated within RBCs
Arg - lys - his - arg is most basic - has has no charge at body pH
Mutated dystrophin gene - less severe - adolescence

48. What causes Down syndrome
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Inc vit B6
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

49. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
32 - malate aspartate shuttle
Inc melt - dec fluidity
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Liver - also in kidney and gut epithelium

50. What is the Name and fxn of vit B12
Carnitine shuttle - acyl - coa from cyto to mito
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Alpha - ketoglutarate dehydrogenase complex
2 rings