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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. 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
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Cytosol
Promotor - TATA box - and CAAT box - AT rich
Williams syndrome

2. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Supply sufficient glucose to brain and RBCs and to preserve protein
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR

3. What does PURe As Gold and CUT The Py stand for
Fibrofatty replacement of muscle - cardiac myopathy
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Purines= A - G pyrimidine = C - T (U)
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates

4. What enzyme converts phenylalanine to tyrosin
Phenylalanine hydroxylase
CGG
Wobble
Kidney - ears - eyes

5. What is the RDE of ketogenesis
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
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
HMG- CoA synthase

6. What does DNA ligase do
Orotic acid to UMP
Seals.
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
Modifies N- oligosaccharides

7. What are the purely ketogenic amino acids
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
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Leu - lys
B100

8. What enzyme does fructose metabolism bypass to reach glycolysis
Free ribosomes
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Alpha and beta tubulin - dimers have two GTP bound
PFK - rate limiting enzyme

9. What are the results of CF on male fertility
Glycine
Males are infertile due to bilateral absence of vas deferens
Poly A polymerase - signal is AAUAA
Coenzyme A - lipoamide

10. Pts with albinism are at inc risk For what cancer
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Skin
Carbomoyl phosphate synthetase II

11. What are uncoupling agents
Colchicine
N to C
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Comlex II

12. 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
Neural tube
Thymic - parathyroid and cardiac
Wobble
Lariat shape in order and remove intron precisely and join 2 exons

13. What does a phosphorylase do
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Adds an inorganic phosphate onto substrate without using ATP

14. What is variable expression and What is an example
Glutamine PRPP amidotransferase
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Unmethylated - newly synthesized - HNPCC
CFTR gene - 7 - Phe 508

15. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Locus heterogeneity - ocular albinism is x- linked recessive
DTMP
Inc melt - dec fluidity

16. What are the glucogenic essential amino acids
LCAT (lecithin cholesterol acyltransferase)
Met - val - arg his
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Cytosol

17. What two rxns in in glycolysis require ATP
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Malonyl coa
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects

18. Where are FADH2 electrons transferred to...
ATP hyrdolysis couple to energetically unfavorable rxns
Oral uridine administration
Comlex II
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

19. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
African Americans and Asians
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Infection - free radicals generated by inflammatory response
Mucus secreting globlet cells and antibody secreting plasma cells

20. Why enzyme breaks down elastin and what enzyme inhibits it
Elastase - inhibited by alpha1 antitrypsin
Removal of N or C termal propeptides from zymogens to generate mature proteins
Poly A polymerase - signal is AAUAA
Glycogen phosphorylase

21. What is the TX for PKU
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Reads usual codon but inserts wrong AA
Changed AA (convservative - new AA is similar in chemical structure)
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

22. What is anticipation and give an example
Core proteins
30 - glycerol -3- phosphate shuttle
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons

23. What is the function of biotin
Microarrays
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

24. What shape does the RNA generate during splicing and why?
CG- 3 > AT-2 - More CG content - melting point goes up
Fibrofatty replacement of muscle - cardiac myopathy
NAD+
Lariat shape in order and remove intron precisely and join 2 exons

25. What is the activated carrier for 1 carbon units
Malapsorption syndromes like sprue or CF or mineral oil intake
Lariat shape in order and remove intron precisely and join 2 exons
Kwashiorkor - small child with swollen belly
THFs

26. What enzyme results in classic galactosemia and What is the clinical
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Chylomicrons

27. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Cre - lox system
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
2pq
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

28. nucleotide repeat for fredreich's ataxia
Foliage - small reserve in liver - eat green leaves
HMG- CoA (HMG- CoA to mevalonate
GAA
After day 1

29. trinucleotide repeat fo myotonic dystrophy
NADPH
CTG
Unmethylated - newly synthesized - HNPCC
Ketone - methyl

30. What causes patau's syndrome and What is it
Phenylalanine hydroxylase
Antioxidant - protects RBCs and membrances from free radical damage
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Specific glycosylases - AP endonuclease

31. Why does alpha amanitin cause liver failure and Where is it found
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Inhibit DNA gyrase specific for prokaryotic topoisomerase
In ER - glucose 6- P to glucose
Inhibits RNA polymerase II - found in death cap mushrooms

32. What is the Hardy Weinberg disease prevalence equation
Oxidative and nonoxidative - no ATP produced or used
Activates LCAT
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
P2 +2pq+ = 1

33. What is the amino acid precursor for catecholamines
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Degredation of TG circulating in chylomicrons and VLDLs
Marasmus - muscle wasting
Phenylalanine

34. Who typically has lactase def
Euchromatin
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
African Americans and Asians

35. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Oxalacetate
SAM
Locus heterogeneity - ocular albinism is x- linked recessive
Oral uridine administration

36. What are the symptoms of vit A def
Acetyl - CoA carboxylase (ACC)
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Night blindness - dry skin
Active secretion in lungs and GI - reabsorbs in skin

37. In a marathon Where does energy come from
Glycogen and FFA oxidation; glucose conserved for final sprinting
FMR1 gene - methylation - associated with chromosomal breakage
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
Particular sequence of DNA where replicatino begins - may be single of multiple

38. What are the results of pancreatic insuff in CF
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
Inc CPK and muscle biopsy
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Malabsorption and steatorrhea (ADEK)

39. characterize autosomal recessive inheritance
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
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
Histidine
THFs

40. In base excision repaire - what recognizes and removes damaged bases and what cuts the DNA to remove the empty sugar
Specific glycosylases - AP endonuclease
Peroxide
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

41. What metabolic rxns occur in both the cytoplasm and mitochondria
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Cri du chat
Glycogen synthase

42. What happens in vit K def
O- oligosaccharaides
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Alkaptonuria - may have debiliating arthralgias
Oxidative and nonoxidative - no ATP produced or used

43. Type II cartilage
CarTWOlage
Phosphorylation - glycosylation - hydroxylation
SnRNPs and other proteins
Basement membrane or basal lamina

44. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Failure to track objects or develop a social smile
B-100 - CII and E
Von gierkes - glucose 6 phosphatase
Neg to pos

45. Give an example of a mitochondrial inherited disease
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Must be both activated and inactivated for cell cycle to progress
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

46. bilateral acoustic schwannomas - juvenile cataracts
NF2 on chromosome 22
Night blindness - dry skin
Hypoxanthine to xanthing and xanthine to uric acid
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

47. What is the RDE of cholesterol synthesis
NAD+
P2 +2pq+ = 1
HMG- CoA reductase
Phenylalanine

48. What defects characterize velocardiofacial syndrome
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
CAG - 4
Palate - facial and cardiac defects
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light

49. What are the 4 assumption of the Hardy Weinberg law
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Phenytoin - MTX - and sulfonamides
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

50. What is maternal PKU
Phenylalanine
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
OTC has hyperammonemia - orotic aciduira does not
B100