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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 does abetalipoproteinemia present and What is the defect
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Read from a fixed starting point as a continuous sequence of bases
Disease
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

2. What is the results of vit B1 def
Alpha 1 -4 glucosidase
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)
Oral uridine administration
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

3. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Huntingtons
Failure to track objects or develop a social smile
Lactate
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

4. What is kartageners syndrome
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Seals.
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

5. What is a nonsense mutation
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Change resulting in early stop codon
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Poly A polymerase - signal is AAUAA

6. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
Anabolic processes as a supply of reducing equivalents
Peroxide
HMG- CoA synthase
Promotor - TATA box - and CAAT box - AT rich

7. What apolipoprotiens are on VLDL
B-100 - CII and E
Myeloperoxidase
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Mitochondria

8. What is the rate determining enzyme (RDE) of glycolysis
Each codon specifies only 1 amino acid
Phosphofructokinase 1
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations

9. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
B-100 - CII and E
Inc CPK and muscle biopsy
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Oligomycin

10. What does the primary transcript combine with to form the spliceosome
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
SnRNPs and other proteins
Krabbes - galactocerebrosidase - galactocerebroside - AR

11. What can vit B3 be used to treat
LDL
Coenzyme A - lipoamide
Hyperlipidemia
Core proteins

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

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13. What inhibits pyruvate kinase
ATP and alanine
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
RRNA
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

14. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
ATP and methionine
Neimann - pick - sphingomyelinase - sphingomyelin - AR
AR
Prevent strands from reannealing

15. Give an example of a mitochondrial inherited disease
Glucose -6 phosphate
4 under the floor
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

16. The pyruvate dehydorgenase complex serves In what reaction: reactants
Pyruvate - NAD+ - CoA
Base + ribose
Core proteins
Glycine - aspartate - glutamine

17. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
Polyneuritis - symmetrical muscle wasting
Oxidative and nonoxidative - no ATP produced or used
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Huntingtons

18. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Lysine and leucine
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Acetyl - CoA
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

19. What is the RDE of glycogen synthesis
Glycogen synthase
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Activates LCAT

20. What is axonemal dynein
Alpha1 antitrypsin
Tryosine hydroxylase
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
TRNA

21. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Stored ATP - creatine phosphate - anaerobic glycolysis
Pseudomonas and s aureus
RRNA
Alpha - ketoglutarate dehydrogenase complex

22. characterize x linked dominant
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
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
APRT + PRPP
Transmitted through both parents - affected mother may have affected children - affected father will have affected children

23. How do odd chain fatty acids participate in gluconeogenesis
Transfers methyl units
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

24. RNA poly can't proofread - but What can it do
Met - val - arg his
Debranching enzyme
LCAT (lecithin cholesterol acyltransferase)
Initiate chains

25. What is the RDE of glycogenolysis
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Glycogen phosphorylase
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

26. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Neurons
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
X linked frame shif mutation
Chylomicrons

27. What is the amino acid precursor for porphyrin and heme
Protein kinase A
HDL
Orotate precursor - with PRPP added later
Glycine

28. What is a missense mutation
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Changed AA (convservative - new AA is similar in chemical structure)
Mebendazole/thiabendazole
ATP - citrate

29. Describe the structure of cilia
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Supply sufficient glucose to brain and RBCs and to preserve protein
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
9+2 arrangement of microtubules

30. What is the Hardy Weinberg disease prevalence equation
Change resulting in early stop codon
HMG- CoA synthase
Liver - ovaries - seminal vesicles
P2 +2pq+ = 1

31. What enzyme results in classic galactosemia and What is the clinical
Inc insulin - dec cAMP - dec PKA
One
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Acetyl - CoA carboxylase (ACC)

32. What is the rate limiting enzyme in cholesterol synthesis
Euchromatin
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
HMG- CoA (HMG- CoA to mevalonate
Ribos first then deoxyribos with ribonucleotide reductase

33. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Williams syndrome
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

34. What 3 steps in RNA processing occur after transcription

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35. How do macrolides and clindamycin work
Dec DNA - dec lymphos leads to SCID
UDP glucose pyrophosphorylase
Binds 50S - blocking translocation
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

36. What enzyme becomes essential in PKU
Tyrosine
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
B100

37. How do aminoglycosides work
Two
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
By inhibiting formation of the initiation complex and cause misreading of mRNA
Proton gradient

38. What does a phosphatase do
Protective against malaria
APC on chromosome 5
Removes phosphate group from substrate
Degredation of TG circulating in chylomicrons and VLDLs

39. What is disulfiram used for
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
2 -4 DNP - aspirin
Biotin

40. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Autosomal recessive diseases
The triphosphate bond
Wrinkles and acne
Breaks down acyl - coa to acetyl coa groups in mito

41. What does fomepizole do
Wrinkles and acne
Exercise: inc NAD/NADH - inc ADP - inc Ca
HMG- CoA reductase
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

42. depression - progressive dementia - choreiform movements - caudate atrophy and dec levels of GABA and ACH in the brain
9+2 arrangement of microtubules
ATP and alanine
Huntingtons
Transfers methyl units

43. characterize autosomal recessive inheritance
MEN - 2A and 2B with ret gene
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
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
They yield only acetyl - CoA equivalents

44. What are the findings with homocystinuria and What amino acid is needs to be supplemented
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Glycogen synthase
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
One

45. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
Malabsorption and steatorrhea (ADEK)
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
CAG - 4
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1

46. What tissue samples are used for karyotyping
Alanine
Blood - bone marrown - amniotic fluid - placental tissue
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Gaucher's - beta glucocerebrosidase - glucocerebrosie - AR

47. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Excess ATP - dATP - feeback inhibits ribonucleotide reductase - no DNA synthesis
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
IDL
Krabbes - galactocerebrosidase - galactocerebroside - AR

48. What does a mischarge tRNA do
Locus heterogeneity - ocular albinism is x- linked recessive
Reads usual codon but inserts wrong AA
Glycogen synthase
Familial hypercholesterolemia - hyperlipidemia type IIA

49. What does DNA poly I do?
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
4 under the floor
Site of steroid synthesis and detoxification of drugs and poisons
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

50. What are CDKs
Mebendazole/thiabendazole
Cyclin dependent kinases;constitutive and inactive
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Activates LCAT