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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. Where is PEP carboxykinase found - What does it do - and What does it require
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
III - joint dislocation - anuerysms - organ rupture
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

2. What substance in egg whites binds biotin
DsRNA promotes degradation of target mRNA knocking down gene expression
Mebendazole/thiabendazole
THFs
Avidin

3. What are the purely ketogenic amino acids
Grows slowly - collapses quickly
Inc melt - dec fluidity
Leu - lys
Dec DNA - dec lymphos leads to SCID

4. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
Ribose 5- P to PRPP
AMP - fructose 2 -6 BP
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Glucose 6 phosphatase

5. Type II collagen
Elastase - inhibited by alpha1 antitrypsin
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Cartilage - hyaline - vitreous body - nucleus pulposus
Familial hypercholesterolemia - hyperlipidemia type IIA

6. What is the Name and function of vit B1
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Actin and myosin
Carnitine acyltransferase I

7. How do macrolides and clindamycin work
Binds 50S - blocking translocation
Alpha1 antitrypsin
Williams syndrome
Dopa decarboxylase

8. What happens to glycogen in the liver
Exons
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels

9. What is axonemal dynein
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Adenosine to inosine
Hypoxanthine to xanthing and xanthine to uric acid
LCAT (lecithin cholesterol acyltransferase)

10. What apolipoproteins are on chylomicrons
B48 - AIV - CII - E
By inhibiting formation of the initiation complex and cause misreading of mRNA
Biotin
Debranching enzyme

11. What does vit E def cause
30 - glycerol -3- phosphate shuttle
Differences in phenotype depend on whether the mutation is of maternal or paternal origin - prader - willi and angelman's syndrome
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Essential fructosuria - fructokinase AR

12. What does the golgi add to serine and threonine residues
Cartilage - hyaline - vitreous body - nucleus pulposus
ATP - citrate
O- oligosaccharaides
2 rings

13. How are the many staggered tropocollagen molecules reinforced
Tuberous sclerosis
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Adds 2 carbon with the help of biotin

14. What are the only purely ketogenic amino acids
Anabolic processes as a supply of reducing equivalents
Lysine and leucine
Initiate chains
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

15. What does DNA ligase do
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Seals.
FMR1 gene - methylation - associated with chromosomal breakage
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

16. What causes B12 def
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Activates LCAT

17. How many ATP are produced by anearobic glycolysis per molecule of glucose
Acetyl - CoA
B100
CG- 3 > AT-2 - More CG content - melting point goes up
Two

18. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
ATP hyrdolysis couple to energetically unfavorable rxns
Blood - bone marrown - amniotic fluid - placental tissue
Essential fructosuria - fructokinase AR
RRNA

19. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Glycine - aspartate - glutamine
Marfans
Isocitrate dehydrogenase
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

20. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

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21. what findings are associated with marfans
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Von Gierke's - Pompe - Cori - McArdle
NADH - NADPH - FADH2

22. bilateral acoustic schwannomas - juvenile cataracts
Glycogenolysis to form glucose
NF2 on chromosome 22
Alkaptonuria - may have debiliating arthralgias
Debranching enzyme

23. what disease can cause pellagra
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
By inhibiting formation of the initiation complex and cause misreading of mRNA
B100 and E
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

24. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
Marasmus - muscle wasting
CAG - 4
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Alpha 1 -6 and alpha 1 -4

25. What happens in termination of proteins synthesis
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Actin and myosin
Stop codon is recognized by release factor - and completed protein is released from ribosome
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA

26. What is the TX for CF and What does it do
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Cofactor for LPL

27. What ribosomes do prokaryotes have
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
30 - 50 - 70
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
Ile - phe - thr - trp

28. What substance inside the cells replenishes NADPH
Biotin
G6PD
Hereditary spherocytosis
Colchicine

29. Which anti gout drugs work on microtubules
Colchicine
Biotin
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
X- linked recessive

30. What is loss of heterozygosity and give an example
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
B100 and E
Wobble
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma

31. What substances induce phosphofructokinase
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Initiate chains
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
AMP - fructose 2 -6 BP

32. What is the RDE of gluconeogenesis
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR
Fructose 1 -6 bisphosphate
Vincritsine/vinblastine
Specific glycosylases - AP endonuclease

33. What causes Hartnup's disease
Niacin - constituent of NAD and NADP - derived from tryptophan
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Glucose -6 phosphate
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells

34. Which direction does dynein go
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Von gierkes - glucose 6 phosphatase
Vincritsine/vinblastine
Post to neg

35. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Oxidizes substrate
Sucrose = glucose + fructose - lactose = glucose + galactose
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Binds 50S - blocking translocation

36. Fluorescent DNA or RNA probe binds to specific gene of interest - used for specific localization of genes and direct visualization of anomalies - like microdeletions - at molecular level
They yield only acetyl - CoA equivalents
RNA
Glycogen and FFA oxidation; glucose conserved for final sprinting
FISH

37. What causes biotin def
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Antibiotic use or excessive ingestion of raw eggs
Unwinds DNA template at replcation fork
Q -

38. Where is glucokinase found - What are the Km and Vmax - and what induces it
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Cyclin dependent kinases;constitutive and inactive
Huntingtons

39. What are Heinz bodies
OTC has hyperammonemia - orotic aciduira does not
32 - malate aspartate shuttle
Oxidized hemoglobin precipiated within RBCs
CAG

40. What is NADPH used for
Hypoxanthine to xanthing and xanthine to uric acid
The triphosphate bond
Lysine and leucine
Anabolic processes as a supply of reducing equivalents

41. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
2 rings
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

42. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Glucose 6 phosphate dehydrogenase (G6PD)
Each codon specifies only 1 amino acid
Von gierkes - glucose 6 phosphatase
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

43. What are purines made from
Disease
IMP precursor
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

44. What enzyme becomes essential in PKU
Tyrosine
B12 and folate
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Hypoglycemia

45. What are the symptoms of vit A def
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Night blindness - dry skin
1 ring
Citrate - acetyl coa from mito to cyto

46. How is orotic aciduria inherited
Nissl body - enzyme and NTs
AR
FMR1 gene - methylation - associated with chromosomal breakage
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

47. What is the activated carrier for aldehyddes
Exons
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
TTP
Each codon specifies only 1 amino acid

48. What is the hardy weinber heterozygote prevalence
Chylomicrons
Glutamine PRPP amidotransferase
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
2pq

49. How do tetracyclines work
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Microtubules
DsRNA promotes degradation of target mRNA knocking down gene expression
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

50. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Same as sprint + OXPHOS
Krabbes - galactocerebrosidase - galactocerebroside - AR
Inc insulin - dec cAMP - dec PKA
Chylomicrons