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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 do the single stranded binding proteins do
Prevent strands from reannealing
RER
Creat a nick in the helix to relieave supercoils created during replication
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

2. Which aspect of the spliceosome do patients with lupus make antibodies against
Each codon specifies only 1 amino acid
Conversion of NE to epi
SnRNPs
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

3. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Glucose 6 phosphate dehydrogenase (G6PD)
Lactate
Lysine and arginine

4. decreases In what substances can cause PKU
B-100 - CII and E
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

5. This is the site where negative regulators bind
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Huntingtons
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Silencers

6. What are the complications/signs of familial hypercholesterolemia
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Huntingtons
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Ketone - methyl

7. Which RNA poly opens DNA at promotor site
Lysine and leucine
RNA poly II
Post to neg
Four

8. What does apoB100 do
Type II
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Binds to LDL receptor - mediates VLDL secretion
Lysine and arginine

9. What two proteins make up microtubules and how are they arranged
Same as sprint + OXPHOS
2 -4 DNP - aspirin
Orotic acid to UMP
Alpha and beta tubulin - dimers have two GTP bound

10. What causes Down syndrome
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Proline and lysine - vit C
Glycine - aspartate - glutamine
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

11. What two rxns in in glycolysis require ATP
Consesus sequenec of base pairs
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Phenylethamolamine N methyl transferase

12. Mild Hurlurs + aggressive behavior no corneal clouding
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

13. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Achondroplasia
Oxalacetate
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
EtOH dehydrogenase and acetaldehyde dehydrogenase

14. Why can't even chain fatty acids produce new glucose
Fructose 1 -6 bisphosphate
Cyclin dependent kinases;constitutive and inactive
They yield only acetyl - CoA equivalents
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

15. What happens in hyperammonemia
FAP
4 under the floor
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

16. What shape does the RNA generate during splicing and why?
5' to 3'
TTP
Lariat shape in order and remove intron precisely and join 2 exons
Malonyl coa

17. What order kinetics does EtOH dehydrogenase have
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Zero
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

18. What does glycosylation of pro alpha chian yield and What is the structure
CAG
Procollagen - triple helix of 3 alpha collagen chains
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Glutamine PRPP amidotransferase

19. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
DTMP
Intermediate filaments
SnRNPs and other proteins
Consesus sequenec of base pairs

20. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
CAG - 4
Two
5' of the incoming nucleotide
Proline and lysine - vit C

21. What happens in carnitine def
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
TRNA
Liver and leafy veggies
Degredation of TG circulating in chylomicrons and VLDLs

22. What does arsenic do and What are th results of poisoning
SnRNPs and other proteins
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Antibiotic use or excessive ingestion of raw eggs

23. What is the breakdown product of dopamine
HVA
Cleft palate - cardiac abnl - pregs test
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Oxidized hemoglobin precipiated within RBCs

24. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
RER
Histidine
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Glycogenolysis to form glucose

25. What apolipoprotein is on LDL
B100
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Dermatitis - alopecia - enteritis
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

26. How do labile celss grow and regenerate and What are examples
HVA
Oxidative is irreversible
Inc melt - dec fluidity
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

27. central and peripheral demyelination with ataxia and dementia
Phosphorylation - glycosylation - hydroxylation
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR
Males are infertile due to bilateral absence of vas deferens
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

28. What substance inside the cells replenishes NADPH
G6PD
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
L form
Glucose 6 phosphatase

29. What does fomepizole do
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Alanine
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Defect in fibrillin

30. In which state is PFK-2 active
Blood - bone marrown - amniotic fluid - placental tissue
Post to neg
Fed
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

31. elevated LDL due to defective or absent LDL receptor - heterozygotes have cholesterol ~300 - homozygotes ~700
Familial hypercholesterolemia - hyperlipidemia type IIA
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Schwann cells - lens - retina - kidneys
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

32. The pyruvate dehydrogenase complex serves In what reaction: products
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Acetly- CoA - CO2 - NADH
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Enhancers

33. Type IV BM
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
4 under the floor
Glycolysis and aerobic respiration
Alkaptonuria - may have debiliating arthralgias

34. What is the composition of urea and where do each part derive from
Neurons
Glucose 6 phosphate dehydrogenase (G6PD)
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

35. What induces pyruvate kinase
F16BP
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
NADH - NADPH - FADH2
CarTWOlage

36. What is the hardy weinber heterozygote prevalence
2pq
Binds 50S - blocking translocation
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Grows slowly - collapses quickly

37. What causes Hartnup's disease
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
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
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Tryptophan

38. What are the water soluble vitamins - which ones are stored
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side

39. Where is vit A found in the diet
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
40 - 60 - 80
Liver and leafy veggies
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels

40. Type III collagen
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Glycogenolysis to form glucose
3' end (with CCA)
Tropoelastin with fibrillin scafolding

41. Name as many x- linked recessive disorders as you can

42. What is the breakdown product of NE
Mucus secreting globlet cells and antibody secreting plasma cells
CFTR gene - 7 - Phe 508
VMA
EtOH dehydrogenase and acetaldehyde dehydrogenase

43. What are cyclin - CDK complexes
Oxidative is irreversible
Inc CPK and muscle biopsy
Must be both activated and inactivated for cell cycle to progress
Silencers

44. What inhibits pyruvate kinase
ATP and alanine
Wobble
Muscle
Fed

45. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Lysine and arginine
FISH
Tuberous sclerosis
NADPH

46. What initiates protein synthesis
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
One
Cofactor for LPL

47. What is the trinucleotide repeat in fragile X
DNA
CGG
Alpha - ketoglutarate dehydrogenase complex
Mutated dystrophin gene - less severe - adolescence

48. Where are cytosolic and organellar proteins made
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
ATP
CG- 3 > AT-2 - More CG content - melting point goes up
Free ribosomes

49. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
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
Base + ribose
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Rb and p53

50. What collagen type is most frequently affected in ehlers danlos and What are common complications
Epithelial cells
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
III - joint dislocation - anuerysms - organ rupture
Fructose 1 -6 bisphosphate