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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. Of the four possible fates for pyruvate - which one carries amino groups to liver from muscle
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Alanine
Liver - ovaries - seminal vesicles

2. What is proteasomal degredation
Arg and his inc in histones Which bind negatively charged DNA
Attachment of ubiquitin to defective proteins tag them for breakdown
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

3. What is the RDE of the HMP shunt
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Deamination
They yield only acetyl - CoA equivalents
Glucose 6 phosphate dehydrogenase (G6PD)

4. 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
Neural tube
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Sulfation

5. Type II collagen
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Microtubules
Cartilage - hyaline - vitreous body - nucleus pulposus
Microarrays

6. What is locus heterogeneity and give an example
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Oxidative is irreversible
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Modifies N- oligosaccharides

7. What are the irreversible enzymes of gluconeogenesis
5' of the incoming nucleotide
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Proton gradient
1 ring

8. 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
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Inc insulin - dec cAMP - dec PKA
Wobble
Vincritsine/vinblastine

9. What is the RDE of fatty acid oxidation
Carnitine acyltransferase I
CAG
Glucose 6 phosphatase
Degradation of TG remaining in IDL

10. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
PCR - denaturation - annealing - elongation
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
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Dermatitis - glossitis - and diarrhea

11. nucleotide repeat for fragile x
Dermatitis - glossitis - and diarrhea
CGG
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin

12. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
Activates LCAT
ATP - citrate
Terminal regions - tropocollagen
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

13. What is the Hardy Weinberg disease prevalence equation
F16BP
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
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
P2 +2pq+ = 1

14. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Rb and p53
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Sucrose = glucose + fructose - lactose = glucose + galactose
Achondroplasia

15. What is the trinucleotide repeat in fragile X
Flank pain - hematuria - HTN - progressive renal failure
CGG
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Facial flushing

16. What happens in carnitine def
LDL
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
Consesus sequenec of base pairs

17. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Removal of N or C termal propeptides from zymogens to generate mature proteins
Lactate
Chylomicrons
G6PD

18. What is the purpose of the HMP shunt
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
RNA poly II
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
1 kind with multiple subunits

19. What is the physiologic role of dystrophin
P+q = 1
Degradation of TG remaining in IDL
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Histidine

20. Type IV collagen is an important structural componenet of the BM for which 3 organs
Uses ATP to add high energy phophate group onto substrate
Bind 30s subunit preventing attachment of aminoacyl - tRNA
SnRNPs
Kidney - ears - eyes

21. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
Cri du chat
Polyneuritis - symmetrical muscle wasting
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

22. What is regeneration of methionine depedent on...
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Conversion of NE to epi
Heterochromatin = HighlyCondensed
B12 and folate

23. What is the structure of elastin
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Tropoelastin with fibrillin scafolding
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
Basement membrane or basal lamina

24. Describe the replication fork
Basement membrane or basal lamina
Antigen - antibody reactivity - can look for antigen or antibody in patients blood
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Tyrosine

25. What does the start codon code for in eukaryotes and prokaryotes
Makes RNA primer on which DNA poly III can initiate replication
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
RNA
Eu - methionine - pro - formyl - methionine

26. What is the Name and fxn of vit B12
Glycolysis and aerobic respiration
Neither of 2 alleles is dominant - blood groups
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

27. What are bite cells and when do you see them
NADH - NADPH - FADH2
Result from phagocytic removal of heinz bodies my macs - G6PD def
Alpha 1 -6 and alpha 1 -4
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

28. In eukaryotes - What does RNA poly I make
Inc insulin - dec cAMP - dec PKA
GTP
Debranching enzyme
RRNA

29. What does the primary transcript combine with to form the spliceosome
Euchromatin
THFs
III - joint dislocation - anuerysms - organ rupture
SnRNPs and other proteins

30. What are the findings in orotic aciduria
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Tuberous sclerosis

31. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Disorder of aromatic amino acid metabolism
Sucrose = glucose + fructose - lactose = glucose + galactose
Tryosine hydroxylase
Neimann - pick - sphingomyelinase - sphingomyelin - AR

32. What does amino acid catabolsim results in the formation of what?
THFs
Cri du chat
30 - glycerol -3- phosphate shuttle
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

33. What does hepatic TG lipase do
Degradation of TG remaining in IDL
Hereditary spherocytosis
Oxidative and nonoxidative - no ATP produced or used
CG- 3 > AT-2 - More CG content - melting point goes up

34. What does beta oxidation do and Where does it occur
Alanine
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Breaks down acyl - coa to acetyl coa groups in mito
Microtubules

35. What happens in vit D excess
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
THFs
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

36. What are the two possible causes of albinism
Mutated dystrophin gene - less severe - adolescence
Purines= A - G pyrimidine = C - T (U)
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

37. Which direction does kinesin go
Neg to pos
NAD+
Disorder of aromatic amino acid metabolism
Oral uridine administration

38. How do permanent cells grow and regenerate and What are examples of permanent cells
Result from phagocytic removal of heinz bodies my macs - G6PD def
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
ATP and methionine
Exercise: inc NAD/NADH - inc ADP - inc Ca

39. What is the Name and function of vit B2
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
GTP
Acetyl - CoA

40. An inability to convert orotic acid to UMP would be caused by a deficiency either of which two enzymes

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41. What is codominance and give an example
Specific glycosylases - AP endonuclease
ATP
CG- 3 > AT-2 - More CG content - melting point goes up
Neither of 2 alleles is dominant - blood groups

42. What are the two transgenic strategies in mice
RNA
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
IMP precursor

43. What part of the pre mRNA contains the actual genetic information coding for protein
Exons
Acetly- CoA - CO2 - NADH
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty

44. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Degradation of TG stored in adipocytes
MRNA
Autosomal recessive diseases
Alanine

45. What is imprinting and give an example

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46. What two enzymes are involved in EtOH metabolism
ATP and methionine
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
EtOH dehydrogenase and acetaldehyde dehydrogenase
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

47. In eukaryotes - What does RNA poly III make
TRNA
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
HMG- CoA reductase
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels

48. FAP is due to deletion On what gene On what chromosome
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
APC on chromosome 5
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

49. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
NADPH
Only processed RNA
Hereditary spherocytosis

50. What is pleiotropy and given an example
FMR1 gene - methylation - associated with chromosomal breakage
Liver - ovaries - seminal vesicles
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
NAD+