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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 are the symptoms of vit A def
Night blindness - dry skin
4 under the floor
Protein kinase A
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

2. What is the TX for pyruvate dehydrogenase deficiency
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Ca/calmodulin in muscle to coordinate with muscle activity
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly

3. What activates the pyruvate dehydrogenase complex
Exercise: inc NAD/NADH - inc ADP - inc Ca
Griseofulvin
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
2 rings

4. What is the composition of urea and where do each part derive from
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Oxidative and nonoxidative - no ATP produced or used
Same AA - often base change in 3rd position of codon (tRNA wobble)

5. What does vit C def cause
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
MRNA - tRNA
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

6. What does high cholesterol or long saturated fatty acid content do to the melting temperature and fluidity
Protein kinase A
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Removes phosphate group from substrate
Inc melt - dec fluidity

7. How do stable (quiescent) cells grow and regenerate and What are examples
Pyruvate to oxaloacetate (3C to 4C)
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
No - its non homologous
Reads usual codon but inserts wrong AA

8. Type I collagen
Inc dicarboxylic acids - dec in glucose and ketones
Initiate chains
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
BOne

9. What are purines made from
Degradation of TG stored in adipocytes
HMP shunt
IMP precursor
Specific glycosylases - AP endonuclease

10. What happens to glycogen in the liver
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Stored ATP - creatine phosphate - anaerobic glycolysis
Must be both activated and inactivated for cell cycle to progress

11. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Inc insulin - dec cAMP - dec PKA
X linked frame shif mutation
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Essential fructosuria - fructokinase AR

12. What is pleiotropy and given an example
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Makes RNA primer on which DNA poly III can initiate replication
Glycogenolysis to form glucose
Degradation of TG stored in adipocytes

13. What is the wernicke - korsakoff clinical picture
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
L form
High output cardiac failure - dilated cardiomyopathy - edema
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss

14. congenital microdeletion of short arm of chromosome 5 with microcephaly - moderate to severe mental retardation - high pitched crying/meying - epicanthal folds - cardiac abnl
Flank pain - hematuria - HTN - progressive renal failure
Glycogen synthase
Vit K antagonist
Cri du chat

15. What are the results of pancreatic insuff in CF
Malabsorption and steatorrhea (ADEK)
Liver hepatocytes and steroid producing cells of the adrenal cortex
Muscle
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR

16. How do cardia glycosides work
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Transfers methyl units
Schilling test
2 rings

17. What are the results of CF on male fertility
Williams syndrome
Cre - lox system
Males are infertile due to bilateral absence of vas deferens
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted

18. What is the amino acid precursor for histamine
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Euchromatin
Tuberous sclerosis
Histidine

19. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Nine
Pyroxidine - converted to pyroxidine phosphate a cofactor used in transamination - decarboxylation - glycogen phosphorylase - cystathionine synthesis and heme synthesis - required for synthesis of niacin and tryptophan
Eu - methionine - pro - formyl - methionine
Karyotyping

20. What substances are uncouling agents
2 -4 DNP - aspirin
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Protein
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE

21. Which antihelminthe drugs work on microtubules
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)
Mebendazole/thiabendazole

22. What is the activated carrier for electrons
Silencers
Elastase - inhibited by alpha1 antitrypsin
NADH - NADPH - FADH2
Phosphofructokinase 1

23. In eukaryotes - What does RNA poly I make
RRNA
ATP hyrdolysis couple to energetically unfavorable rxns
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Orotic acid to UMP

24. What causes Hartnup's disease
PCR - denaturation - annealing - elongation
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
UDP glucose pyrophosphorylase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

25. How many rings do pyrimidines have
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
1 ring
Malapsorption syndromes like sprue or CF or mineral oil intake
CGG

26. What does universal genetic code refer to and What are some exception
RNA
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
Cytosol
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

27. What is the amino acid precuror for creatine - urea and nitric oxide
Arginine
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Neurons
UDP glucose pyrophosphorylase

28. What does the addition of mannose -6 phosphate do
Targets the proteins for lysosome
Alpha 1 -6 and alpha 1 -4
Tuberous sclerosis
CAG

29. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Reads usual codon but inserts wrong AA
Autosomal recessive diseases
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
BOne

30. What 3 steps in RNA processing occur after transcription

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31. What happens in vit D excess
VLDL
1 kind with multiple subunits
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21

32. How do you diagnose CFTR
Glucose 6 phosphatase
Inc Cl - in sweat
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase

33. What is heteroplasmy
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

34. Why can't muscle produce in gluconeogenesis
Ribos first then deoxyribos with ribonucleotide reductase
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Lacks glucose 6 phophatase
Hypoxanthine to xanthing and xanthine to uric acid

35. Why enzyme breaks down elastin and what enzyme inhibits it
Antioxidant - protects RBCs and membrances from free radical damage
Elastase - inhibited by alpha1 antitrypsin
Inhibits RNA polymerase II - found in death cap mushrooms
MRNA - tRNA

36. What does GFAP stain for
Dec DNA - dec lymphos leads to SCID
Neither of 2 alleles is dominant - blood groups
Neuralgia
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

37. What are the functinos of vitamin A
Paclitaxel
CarTWOlage
Breaks down acyl - coa to acetyl coa groups in mito
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

38. What are the 3 AR forms of homocystinuria
RNA poly II
Mediates extra remnant take up
Microarrays
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

39. Where do you find elastin and What does it do
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.

40. What does a western blot use for its sample
Protein
Phenytoin - MTX - and sulfonamides
Ile - phe - thr - trp
Neither of 2 alleles is dominant - blood groups

41. What are ketone bodies made from - where are they metabolized and how are they excreted
Dopa decarboxylase
Phenylethamolamine N methyl transferase
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Ribos first then deoxyribos with ribonucleotide reductase

42. What does DNA poly I do?
Alanine
GTP
UGA - UAA and UAG
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

43. bilateral acoustic schwannomas - juvenile cataracts
NF2 on chromosome 22
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

44. What is the Name and function of vit B1
Prokaryotic only - elongates leading strand by adding deoxnucTIDE to the 3' end. Elongates lagging strand until it reaches primer of preceeding fragment. 3' to 5' exonuclease activity 'proofreads' each added nucTIDE
Seals.
NADH - NADPH - FADH2
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase

45. cardiomegaly - systemic findings leading to early death - dz and enzyme

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46. What is the RDE of cholesterol synthesis
P+q = 1
Fibrofatty replacement of muscle - cardiac myopathy
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
HMG- CoA reductase

47. What does CATCH 22 stand for and What causes is...
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Asp and Glu
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
Tryosine hydroxylase

48. Which direction does dynein go
Alpha1 antitrypsin
Post to neg
Phosphofructokinase 1
CG- 3 > AT-2 - More CG content - melting point goes up

49. What happens in hyperammonemia
Muscle
Leu - lys
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
ATP

50. What is proteasomal degredation
After citruline
Attachment of ubiquitin to defective proteins tag them for breakdown
CTG
CGG