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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 does helicase do
CGG
Leu - lys
Unwinds DNA template at replcation fork
Change resulting in early stop codon

2. What is kartageners syndrome
NAD+
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Polycystic liver disease - berry aneurysm - mitral valve prolapse

3. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Heterochromatin = HighlyCondensed
CFTR gene - 7 - Phe 508
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Phosphorylation - glycosylation - hydroxylation

4. What is NADPH used for
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Anabolic processes as a supply of reducing equivalents
Ca/calmodulin in muscle to coordinate with muscle activity
FISH

5. What does vit E def cause
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
NADPH

6. 1 g of protein or cabrohydrate = ?kcal
Four
2 -4 DNP - aspirin
Post to neg
Glycogen phosphorylase

7. What does a carboxylase do
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Adds 2 carbon with the help of biotin
30 - glycerol -3- phosphate shuttle
Binds 50S - blocking translocation

8. What enzyme adds Cl - to the H202 to makes bleach
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Myeloperoxidase

9. What metabolic rxns occur in both the cytoplasm and mitochondria
Robertsonian translocation and mosaicism
VLDL
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

10. What do B- complex vitamin deficiencies often result in
Cartilage - hyaline - vitreous body - nucleus pulposus
Dermatitis - glossitis - and diarrhea
Mebendazole/thiabendazole
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

11. What causes biotin def
Antibiotic use or excessive ingestion of raw eggs
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
ATP and methionine
Transmitted only through mother - all offspring of affected females may show signs of disease

12. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Neurofibromatosis type 1 (von Recklinghausens disease)
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
B100

13. Which are the basic amino acids
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Kwashiorkor - small child with swollen belly
VMA
Arg - lys - his - arg is most basic - has has no charge at body pH

14. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
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
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Krabbes - galactocerebrosidase - galactocerebroside - AR
HMG- CoA synthase

15. What does degenerate/rundant genetic code refer to...
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
Microarrays
MRNA
More than 1 codon may code for the same amino acid

16. What does a phosphatase do
Removes phosphate group from substrate
CAG
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
1 -25 OH2 D3 = calcitriol

17. What happens on the nonoxidative arm of the HMP shunt and What is the key enzyme and cofactor
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
Tryptophan
Procollagen - triple helix of 3 alpha collagen chains
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1

18. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
Degredation of TG circulating in chylomicrons and VLDLs
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Neuralgia
Promotor - TATA box - and CAAT box - AT rich

19. What is the TX for CF and What does it do
IDL
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Core proteins
Liver and leafy veggies

20. What shuttle is used in fatty acid degredation and What does it move and From where to where
Mcardle's - skeletal muscle glycogen posphorylase
Carnitine shuttle - acyl - coa from cyto to mito
9+2 arrangement of microtubules
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

21. What is the most common urea cycle disorder and What is the mode of inheritance?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Degradation of TG remaining in IDL
HMG- CoA reductase
PMNs

22. What is the activated carrier for Co2
Defect in fibrillin
Biotin
Adenosine to inosine
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)

23. How many rings do pyrimidines have
Carnitine acyltransferase I
1 ring
Liver - ovaries - seminal vesicles
CFTR gene - 7 - Phe 508

24. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
9+2 arrangement of microtubules
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

25. What does inc phenylalanine lead to...
X- linked recessive
Phenylketones in urine
Cri du chat
After day 1

26. What does a defective Cl channel do
B100
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Leu - lys

27. What happens in the first stage of collagen synthesis - and Where does it happen
Polyneuritis - symmetrical muscle wasting
Read from a fixed starting point as a continuous sequence of bases
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Night blindness - dry skin

28. What tissues have only aldose reductase
N to C
APC on chromosome 5
Schwann cells - lens - retina - kidneys
One

29. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Dermatitis - glossitis - and diarrhea
Neg to pos
Infection - free radicals generated by inflammatory response
B12 and folate

30. What is the longest time of RNA and shortest
Uses ATP to add high energy phophate group onto substrate
Prevent strands from reannealing
MRNA - tRNA
FISH

31. Accurate base pairing is required only in the first two nucleotide positions of an mRNA codon - so conds differeing in the 3rd position may code for the same tRNA/AA due to degenerate genetic code
Wobble
Oxidizes substrate
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

32. Delivers dietary TGs to peripheral tissues - delivers cholesterol to liver in the form of remnants - mostly depleted of TGs - secreted by intestinal epith cells
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Chylomicrons

33. What two rxns in in glycolysis require ATP
Removal of N or C termal propeptides from zymogens to generate mature proteins
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

34. What is the treatment for cystathionine synthase def
Base + ribose + phosphate (3' -5') phosphodiester bond
Dec methionine - inc cystiene - inc B12/folate
Inhibits the Na/K pump by binding the K side
ATP and alanine

35. What happens in a B12 def
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Bind 30s subunit preventing attachment of aminoacyl - tRNA
B-100 - CII and E
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

36. How does ouabain work
Inhibits the Na/K pump by binding the K side
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

37. What is the purpose of the HMP shunt
UDP glucose pyrophosphorylase
ATP and methionine
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
HMG- CoA reductase

38. What does CATCH 22 stand for and What causes is...
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Neither of 2 alleles is dominant - blood groups
Lacks glucose 6 phophatase
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

39. RNA poly can't proofread - but What can it do
Initiate chains
Must be both activated and inactivated for cell cycle to progress
One
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

40. Where are FADH2 electrons transferred to...
Comlex II
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Ribose 5- P to PRPP
B6

41. How do labile celss grow and regenerate and What are examples
One
Sulfation
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Neither of 2 alleles is dominant - blood groups

42. 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
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
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
N to C

43. What is the wernicke - korsakoff clinical picture
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)
Mutated dystrophin gene - less severe - adolescence
By inhibiting formation of the initiation complex and cause misreading of mRNA
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

44. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Orotic acid to UMP
Oxidizes substrate
SnRNPs

45. What is imprinting and give an example

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46. What two proteins make up microtubules and how are they arranged
Alpha and beta tubulin - dimers have two GTP bound
Fructose 1 -6 bisphosphate
Night blindness - dry skin
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)

47. NADPH are used In what 4 things
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
B12 and folate
APRT + PRPP
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

48. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
1 -25 OH2 D3 = calcitriol
Hypoglycemia
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Sulfation

49. How do odd chain fatty acids participate in gluconeogenesis
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Actin and myosin
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
THFs

50. bilateral acoustic schwannomas - juvenile cataracts
NF2 on chromosome 22
Glucose 6 phosphate dehydrogenase (G6PD)
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs