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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. What is the treatment for dec affinity of cystathionine synthase for pyroxidal phosphate
Inc vit B6
CTG
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Modifies N- oligosaccharides

2. What enzyme degrades a small amount of glycogen in lysosomes
Alpha 1 -4 glucosidase
LDL
Males are infertile due to bilateral absence of vas deferens
Malonyl coa

3. What is incomplete penetrence and give an example
Not all individuals with a mutant genotype show the mutant phenotype
Phenylketones in urine
NAD+
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact

4. several distinct syndromes characterized by familial tumors of endocrine glands including pancreas - parathyroid - pituitary - thryoid and adrenal medulla - disorders and gene association
CTG
MEN - 2A and 2B with ret gene
Inc CPK and muscle biopsy
Proline and glycine (non glycosylated forms)

5. In which state is PFK-2 active
Fed
Facial flushing
Glucose 6 phosphate dehydrogenase (G6PD)
Ribose 5- P to PRPP

6. Wgat substances directly inhibit mitochondrial ATPase - causing an inc in proton gradient - no ATP because pump is stopped
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
II - VII - IX - X (1972) protein C and S
Oligomycin
1 kind with multiple subunits

7. What does apoE do
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Met - val - arg his
Mutated dystrophin gene - less severe - adolescence
Mediates extra remnant take up

8. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Failure to track objects or develop a social smile
1 ring
RER

9. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Karyotyping
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Defect in fibrillin
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

10. How does OTC def present
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
Infection - free radicals generated by inflammatory response
B-100 - CII and E

11. What other inflammatory process can induce a hemolytic anemia in NADPH defieicnt patients
Infection - free radicals generated by inflammatory response
17 - 17 letters in von Recklinghausen
Dopa decarboxylase
Krabbes - galactocerebrosidase - galactocerebroside - AR

12. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
Same AA - often base change in 3rd position of codon (tRNA wobble)

13. What feedback inhibits hexokinase
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Cytosol
Glucose -6 phosphate
Degredation of dietary TG in small intestine

14. What does glycosylation of pro alpha chian yield and What is the structure
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Creat a nick in the helix to relieave supercoils created during replication
Procollagen - triple helix of 3 alpha collagen chains
Regulatory proteins that control cell cycle events; phase specific; activate CDKs

15. Describe robertsonian translocation
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Keep glutathione reduced so it can detoxify free radicals and peroxides
Hurlers syndrome - alpha L iduronidase - heparan sulfate/dermatan sulfate - AR
Phosphofructokinase 1

16. in a 100 meter sprint Where does energy come from
Orotate precursor - with PRPP added later
Phenylalanine hydroxylase
Stored ATP - creatine phosphate - anaerobic glycolysis
Vit K antagonist

17. What is the activated carrier for 1 carbon units
DsRNA promotes degradation of target mRNA knocking down gene expression
Polycystic liver disease - berry aneurysm - mitral valve prolapse
High output cardiac failure - dilated cardiomyopathy - edema
THFs

18. What is pseudohypertrophy in the calf a result of - and What are the cardiac manifestations
Fibrofatty replacement of muscle - cardiac myopathy
Tyrosine
Oxalacetate
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

19. What is trimming
Removal of N or C termal propeptides from zymogens to generate mature proteins
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
VLDL

20. What is the result of vit B5 def
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Dermatitis - enteritis - alopecia - adrenal insuff
Foliage - small reserve in liver - eat green leaves
Wernicke - korsakoff - dry and wet beriberi

21. What two amino acids are required druing periods of growth and why
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes
Arg and his inc in histones Which bind negatively charged DNA
More than 1 codon may code for the same amino acid
Carbomoyl phosphate synthetase II

22. What form of amino acids are found in proteins
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
L form
Attachment of ubiquitin to defective proteins tag them for breakdown
Metanephrine

23. What does biotin def cause
Modifies N- oligosaccharides
Actin and myosin
Dermatitis - alopecia - enteritis
Kwashiorkor - small child with swollen belly

24. What are the characteristics of angelmans syndrome and How does it occur
Disorder of aromatic amino acid metabolism
HDL
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

25. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
Hypoxanthine to xanthing and xanthine to uric acid
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
IDL
Base + ribose

26. characterize mitochondrial inheritance
Infection - free radicals generated by inflammatory response
Alpha 1 -4 glucosidase
Transmitted only through mother - all offspring of affected females may show signs of disease
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

27. What are cyclins
Polyneuritis - symmetrical muscle wasting
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Proline and lysine - vit C
GTP

28. Type III collagen
Glycogen phosphorylase
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Isocitrate dehydrogenase
VLDL

29. What creates the musty body odor in PKU
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Disorder of aromatic amino acid metabolism
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
Oxidized hemoglobin precipiated within RBCs

30. What are the purely ketogenic amino acids
Heterochromatin = HighlyCondensed
Only processed RNA
Leu - lys
Robertsonian translocation and mosaicism

31. colon becomes covered witih adenomatous polyps after puberty - progresses to colon cancer unless resected
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Williams syndrome
Covalent cross - linking by lysyl oxidase to make collagen fibrils
FAP

32. What is pleiotropy and given an example
P2 +2pq+ = 1
HMP shunt
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Tropoelastin with fibrillin scafolding

33. In which state is FBPase -2 active
Kwashiorkor - small child with swollen belly
Fasting
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Protein kinase A

34. What does the golgi assemble proteoglycans from
Hyperlipidemia
Keep glutathione reduced so it can detoxify free radicals and peroxides
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Core proteins

35. What is the defectin IV - hypertriglyceridemia
SnRNPs and other proteins
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
APC on chromosome 5
Must be both activated and inactivated for cell cycle to progress

36. What is the RER called in neurons and What is made there
Cofactor for LPL
Griseofulvin
HMP shunt
Nissl body - enzyme and NTs

37. What is the source of energy in the fasting state between meals
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
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle

38. What is a frame shift
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Alkaptonuria - may have debiliating arthralgias
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Protein

39. 1 g of protein or cabrohydrate = ?kcal
Four
DNA
Inc CPK and muscle biopsy
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)

40. What does the primary transcript combine with to form the spliceosome
Uses ATP to add high energy phophate group onto substrate
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Catabolic processes to carry reducing equivalents away as NADH
SnRNPs and other proteins

41. RNA poly can't proofread - but What can it do
Initiate chains
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Dermatitis - enteritis - alopecia - adrenal insuff
Breaks down acyl - coa to acetyl coa groups in mito

42. In what cells do the respiratory burst occur
Unwinds DNA template at replcation fork
PMNs
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
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

43. What is the breakdown product of epi
Base + ribose
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Metanephrine
Ile - phe - thr - trp

44. What are the function of vit C
HGPRT - defective purine salvage - excess uric acid production
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
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Supply sufficient glucose to brain and RBCs and to preserve protein

45. What is the most common urea cycle disorder and What is the mode of inheritance?
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
3' end (with CCA)

46. What is the defect in fructose intolerance and What does it cause
Medial dorsal nucleus of thalamus - mamillary bodies
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

47. What are uncoupling agents
Liver - also in kidney and gut epithelium
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
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

48. What does the deletion of the dystrophin gene lead to...
Unwinds DNA template at replcation fork
L form
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Accelearted muscle breakdown

49. Which RNA poly opens DNA at promotor site
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
RNA poly II
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis

50. What does the golgi apparatus do on asparagine
Modifies N- oligosaccharides
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
2 rings
Microarrays