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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. In which state is PFK-2 active
Glycogen synthase
Site of steroid synthesis and detoxification of drugs and poisons
Inc melt - dec fluidity
Fed

2. What is the RDE of gluconeogenesis
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Unwinds DNA template at replcation fork
Fructose 1 -6 bisphosphate

3. Type IV BM
HVA
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
4 under the floor

4. What is the fxn of vit D
Glucose - 2Pi - 2ADP - 2NAD+
More than 1 codon may code for the same amino acid
Alpha 1 -4 glucosidase
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

5. What two proteins make up microtubules and how are they arranged
Acetyl - CoA
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Alpha and beta tubulin - dimers have two GTP bound

6. What can excess vit B3 cause
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Facial flushing
Phosphofructokinase 1
Rb and p53

7. What produces NADPH
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
HMP shunt
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

8. Milder form of type I with nl blood lactate levels - dz and enzyme

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9. What does lipoprotein lipase do
Lysine and arginine
Degredation of TG circulating in chylomicrons and VLDLs
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Cartilage - hyaline - vitreous body - nucleus pulposus

10. What is the RDE of fatty acid oxidation
Carnitine acyltransferase I
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
AMP - fructose 2 -6 BP
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

11. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Fasting
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Procollagen - triple helix of 3 alpha collagen chains
Oxidative and nonoxidative - no ATP produced or used

12. What is loss of heterozygosity and give an example
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Carbomoyl phosphate synthetase II
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
Fasting

13. What are Heinz bodies
Oxidized hemoglobin precipiated within RBCs
Active secretion in lungs and GI - reabsorbs in skin
Reads usual codon but inserts wrong AA
GTP

14. A small proportion of Down syndrome is due to What two genetic events
Phenylethamolamine N methyl transferase
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Robertsonian translocation and mosaicism
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

15. What occurs to oxaloacetate in starvation and DKA
Inc insulin - dec cAMP - dec PKA
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Carnitine acyltransferase I

16. What does arsenic do and What are th results of poisoning
Makes RNA primer on which DNA poly III can initiate replication
Methionine encode by only 1 codon (AUG)
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Inhibits lipoic acid - vomiting - rice water stools - garlic breath

17. what disease can cause pellagra
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Ile - phe - thr - trp
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
Vincritsine/vinblastine

18. What are the symptoms of vit A excess
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
IMP precursor
Ile - phe - thr - trp
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT

19. What is the physiologic role of dystrophin
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
Abnormal protein folding - degradation before reaching cell surface
Anchor muscle fibers - primarily in skeletal and cardiac muscle
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

20. Which phase of the HMP shunt is reversible and Which is irreversible
No
Oxidative is irreversible
Neg to pos
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

21. Type II cartilage
After day 1
CarTWOlage
Coenzyme A - lipoamide
Alpha 1 -4 glucosidase

22. What is the amino acid precuror for creatine - urea and nitric oxide
EtOH dehydrogenase and acetaldehyde dehydrogenase
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Arginine
Thymic - parathyroid and cardiac

23. How do tetracyclines work
VMA
Asp and Glu
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Arginine

24. What is the breakdown product of NE
Same as sprint + OXPHOS
VMA
Uses ATP to add high energy phophate group onto substrate
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea

25. FAP is due to deletion On what gene On what chromosome
Defect in fibrillin
Glycogenolysis to form glucose
Dec DNA - dec lymphos leads to SCID
APC on chromosome 5

26. Which amino acids are elastin rich in
Phosphofructokinase 1
Proline and glycine (non glycosylated forms)
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Marasmus - muscle wasting

27. Which bond is stronger AT or CG and why? What is the laboratory consequence of this?
CG- 3 > AT-2 - More CG content - melting point goes up
O- oligosaccharaides
PFK - rate limiting enzyme
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

28. In eukaryotes - What does RNA poly III make
Four
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
TRNA
Connective tissue

29. What liberates glucose from glucose 6 P
Marasmus - muscle wasting
Glucose 6 phosphatase
Changed AA (convservative - new AA is similar in chemical structure)
Acetoacetate and beta hydroxybutyrate

30. What is the origin of replication
Particular sequence of DNA where replicatino begins - may be single of multiple
Tryosine hydroxylase
G6PD
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP

31. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Neither of 2 alleles is dominant - blood groups
Oxalacetate
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

32. What does vit E def cause
Transmitted only through mother - all offspring of affected females may show signs of disease
VLDL
O- oligosaccharaides
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

33. What happens at the smooth ER
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Site of steroid synthesis and detoxification of drugs and poisons
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

34. Type I bone
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Arg - lys - his - arg is most basic - has has no charge at body pH
BOne
RNA poly II

35. What does PURe As Gold and CUT The Py stand for
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Purines= A - G pyrimidine = C - T (U)
30 - glycerol -3- phosphate shuttle
X linked frame shif mutation

36. Which are the acidic amino acids
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Asp and Glu
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Dopa decarboxylase

37. What is maternal PKU
Acetyl - CoA to malonyl - CoA (2C to 3C)
Vit K antagonist
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Abnormal protein folding - degradation before reaching cell surface

38. Acetyl - CoA carboxylase catalyzes what rxn
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Acetyl - CoA to malonyl - CoA (2C to 3C)
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

39. Where is pyruvate carboxylase found - What does it do - What does it require amd What activates it
HGPRT - defective purine salvage - excess uric acid production
Makes RNA primer on which DNA poly III can initiate replication
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
IDL

40. What is incomplete penetrence and give an example
Not all individuals with a mutant genotype show the mutant phenotype
Carbomoyl phosphate synthetase I
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Fibrofatty replacement of muscle - cardiac myopathy

41. What is the RDE of ketogenesis
HMG- CoA synthase
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora

42. What causes Marfan syndrome
Arginine
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Defect in fibrillin
Glucose -6 phosphate

43. What are the irreversible enzymes of gluconeogenesis
Cartilage - hyaline - vitreous body - nucleus pulposus
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

44. What is the defectin IV - hypertriglyceridemia
Phenylalanine
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
G6PD
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

45. What enzymes metabolize fatty acids and amino acids
Glycogen synthase
Acetoacetate and beta hydroxybutyrate
Anabolic processes as a supply of reducing equivalents
Pyruvate to oxaloacetate (3C to 4C)

46. characterize autosomal recessive inheritance
Two
Glycine - aspartate - glutamine
Stored ATP - creatine phosphate - anaerobic glycolysis
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

47. What does apoCII do
HMG- CoA synthase
Cofactor for LPL
III - joint dislocation - anuerysms - organ rupture
Initiate chains

48. How do stable (quiescent) cells grow and regenerate and What are examples
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Niacin - constituent of NAD and NADP - derived from tryptophan
Ribos first then deoxyribos with ribonucleotide reductase
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

49. What are the two transgenic strategies in mice
HDL
Creat a nick in the helix to relieave supercoils created during replication
1 ring
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

50. What are the results of pancreatic insuff in CF
Post to neg
Base + ribose
ATP - citrate
Malabsorption and steatorrhea (ADEK)