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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 lipoprotein lipase do
Consesus sequenec of base pairs
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Blood - bone marrown - amniotic fluid - placental tissue
Degredation of TG circulating in chylomicrons and VLDLs

2. What is the amino acid precursor for histamine
Lacks glucose 6 phophatase
2pq
Histidine
UDP glucose pyrophosphorylase

3. What enzyme converts adenine to AMP
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Tyrosine
Semiconservative - continuous and discontinuous strands (okazaki fragments)
APRT + PRPP

4. What does hartnups disease cause
Creat a nick in the helix to relieave supercoils created during replication
Consesus sequenec of base pairs
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

5. What enzyme converts glucose 1 p to UDP glucose
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
Adds 2 carbon with the help of biotin
UDP glucose pyrophosphorylase
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected

6. antbiotic controlled promoter to induciblly manipulate genes at specific developmental points
Inc insulin - dec cAMP - dec PKA
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Cre - lox system

7. What is the energy source after day 3 of starvation
SnRNPs
Prevent strands from reannealing
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death
Result from phagocytic removal of heinz bodies my macs - G6PD def

8. spheroid RBCs due to spectrin or ankyrin defect - hemolytic anemia - inc MHCH - splenectomy is curative
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Polyneuritis - symmetrical muscle wasting
Hereditary spherocytosis
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1

9. facial lesions - hypopigmented 'ash leaf spots -' cortical and retinal hamartomas - seizures - mental retardation - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas - inc risk of astrocytomas
Inc CPK and muscle biopsy
Metanephrine
Fibrofatty replacement of muscle - cardiac myopathy
Tuberous sclerosis

10. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
RER
RNA
Rotenone - CN- - antimycin A - CO
3 NADH - 1 FADH2 - 2 CO2 - 1 GTP = 12 ATP (x2 per glucose)

11. decreases In what substances can cause PKU
Locus heterogeneity - ocular albinism is x- linked recessive
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Niacin - constituent of NAD and NADP - derived from tryptophan

12. What are the only purely ketogenic amino acids
Lysine and leucine
In ER - glucose 6- P to glucose
Dermatitis - enteritis - alopecia - adrenal insuff
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation

13. Which anti breast cancer drugs work on micortubules
Paclitaxel
DsRNA promotes degradation of target mRNA knocking down gene expression
Arg and his inc in histones Which bind negatively charged DNA
Skin

14. What occurs to oxaloacetate in starvation and DKA
Q -
Unmethylated - newly synthesized - HNPCC
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

15. Where are cytosolic and organellar proteins made
Alpha and beta tubulin - dimers have two GTP bound
Malapsorption syndromes like sprue or CF or mineral oil intake
Intermediate filaments
Free ribosomes

16. What is the activated carrier for Co2
Biotin
Acetyl - CoA
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Procollagen - triple helix of 3 alpha collagen chains

17. What produces NADPH
Basement membrane or basal lamina
DNA
HMP shunt
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

18. Do balanced translocations cause abnl phenotype
Unmethylated - newly synthesized - HNPCC
4 under the floor
No
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

19. What substance accumulates in galactokinase def and What is the clinical picture
Neuralgia
Superoxide dismutase
Base + ribose + phosphate (3' -5') phosphodiester bond
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

20. What form of amino acids are found in proteins
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
L form
Inc CPK and muscle biopsy
Alcohol version of glucose - can trap glucose in cell - aldose reductase

21. What does Ehlers Danlos cause and why
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Blood - bone marrown - amniotic fluid - placental tissue
ATP
Basement membrane or basal lamina

22. What does the deletion of the dystrophin gene lead to...
Peroxide
Liver - ovaries - seminal vesicles
Accelearted muscle breakdown
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

23. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
Conversion of NE to epi
Alpha 1 -4 glucosidase
1 ring

24. What happens in hyperammonemia
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
CGG
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

25. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Acetyl - CoA
Carnitine shuttle - acyl - coa from cyto to mito
Result from phagocytic removal of heinz bodies my macs - G6PD def
Fibrofatty replacement of muscle - cardiac myopathy

26. What chromosome is the NF gene on...
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Inc vit B6
17 - 17 letters in von Recklinghausen
Grows slowly - collapses quickly

27. What does the primary transcript combine with to form the spliceosome
SnRNPs and other proteins
Inhibits the Na/K pump by binding the K side
Glucose 6 phosphate dehydrogenase (G6PD)
Alcohol version of glucose - can trap glucose in cell - aldose reductase

28. What do neurofilaments stain for
Kwashiorkor - small child with swollen belly
Neurons
Result from phagocytic removal of heinz bodies my macs - G6PD def
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

29. What two amino acids are required druing periods of growth and why
Neg to pos
CFTR gene - 7 - Phe 508
Arg and his inc in histones Which bind negatively charged DNA
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

30. What CETP do
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Glucose -6 phosphate
Neural tube
Purines= A - G pyrimidine = C - T (U)

31. What is the complication of cystinuria
HMG- CoA reductase
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Inc glucagon - inc cAMP - inc PKA

32. What causes biotin def
Antibiotic use or excessive ingestion of raw eggs
SnRNPs and other proteins
Peroxide
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

33. How do microtubules grow and collapse
Phenylethamolamine N methyl transferase
Ribose 5- P to PRPP
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Grows slowly - collapses quickly

34. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Methionine encode by only 1 codon (AUG)
1 kind with multiple subunits
X linked frame shif mutation

35. Why is G6PD def more common among patients of african decent
Protective against malaria
Silencers
LCAT (lecithin cholesterol acyltransferase)
Antibiotic use or excessive ingestion of raw eggs

36. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Inc glucagon - inc cAMP - inc PKA
9+2 arrangement of microtubules
Kwashiorkor - small child with swollen belly
Marfans

37. What components come together to make S- adenosyl methionine
5' to 3'
Free ribosomes
Makes RNA primer on which DNA poly III can initiate replication
ATP and methionine

38. Which tumor suppresors inhibit G1 to S progression - where mutations result in unrestrained growth
Orotate precursor - with PRPP added later
More than 1 codon may code for the same amino acid
Rb and p53
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol

39. What causes B12 def
Deamination
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

40. What activates the pyruvate dehydrogenase complex
Exercise: inc NAD/NADH - inc ADP - inc Ca
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
MRNA
CGG

41. What is used to diagnose muscular dystrophies
Inc CPK and muscle biopsy
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

42. What is the active form of vit D
1 -25 OH2 D3 = calcitriol
O- oligosaccharaides
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
RNA poly II

43. When does aspartate enter the urea cycle
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Disease
Alpha1 antitrypsin
After citruline

44. What is the RER called in neurons and What is made there
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
RNA
Nissl body - enzyme and NTs
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

45. characterize autosomal recessive inheritance
Consesus sequenec of base pairs
Orotate precursor - with PRPP added later
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
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

46. Name as many x- linked recessive disorders as you can

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47. What step begins the urea cycle and What is the enzyme needed - Where does it happen
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
NAD+
Each codon specifies only 1 amino acid
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

48. What does DNA poly I do?
Cre - lox system
Tryptophan
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
25OHD3

49. What are the 4 assumption of the Hardy Weinberg law
Each codon specifies only 1 amino acid
Euchromatin
RRNA
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

50. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
Acetyl - CoA carboxylase (ACC)
Disorder of aromatic amino acid metabolism
Krabbes - galactocerebrosidase - galactocerebroside - AR
Attachment of ubiquitin to defective proteins tag them for breakdown