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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 exception to genetic redundancy
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
HGPRT - defective purine salvage - excess uric acid production
Methionine encode by only 1 codon (AUG)

2. Leysh - Nyhan syndrome is a defect in which enzyme and What are the biochemical results
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
II - VII - IX - X (1972) protein C and S
HGPRT - defective purine salvage - excess uric acid production
Targets the proteins for lysosome

3. What is the RDE of glycogen synthesis
Transmitted only through mother - all offspring of affected females may show signs of disease
Oxidized hemoglobin precipiated within RBCs
Glycogen synthase
Arg and his inc in histones Which bind negatively charged DNA

4. What does a defective Cl channel do
Night blindness - dry skin
Zero
Comlex II
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

5. In a 1000 meter run - Where does energy come from
Same as sprint + OXPHOS
ATP and methionine
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Oxidizes substrate

6. What do B- complex vitamin deficiencies often result in
Inc intestinal absorption fo calcium and phosphate - inc bone resorption
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Dermatitis - glossitis - and diarrhea
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

7. What enzyme def can cause emphysema
Alpha1 antitrypsin
ADPKD
Colchicine
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

8. Describe the structure of cilia
Degredation of dietary TG in small intestine
9+2 arrangement of microtubules
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Lacks glucose 6 phophatase

9. Synthesis of vit B3 requires what other vitamin
Catabolic processes to carry reducing equivalents away as NADH
B6
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
APKD1 on chromosome 16

10. What is the most common urea cycle disorder and What is the mode of inheritance?
Isocitrate dehydrogenase
Krabbes - galactocerebrosidase - galactocerebroside - AR
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

11. What do def in in enzymes of gluconeogenesis cause
Asp and Glu
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Hypoglycemia
Fibrofatty replacement of muscle - cardiac myopathy

12. What are purines made from
Binds to LDL receptor - mediates VLDL secretion
In ER - glucose 6- P to glucose
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
IMP precursor

13. What does a phosphorylase do
Change resulting in early stop codon
Targets the proteins for lysosome
Malonyl coa
Adds an inorganic phosphate onto substrate without using ATP

14. What is the amino acid precuros for niacin and serotonin/melatonin
Tryptophan
ATP and alanine
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Wernicke - korsakoff - dry and wet beriberi

15. What happens in vit B2 def
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization
Ribose 5- P to PRPP
Wernicke - korsakoff - dry and wet beriberi
Mediates extra remnant take up

16. What substances directly inhibit electron transport chain
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Disease
Rotenone - CN- - antimycin A - CO

17. bilateral - massive enlargement of of kidneys due to multiple large cysts
Diphyllobothrium latum
Acetly- CoA - CO2 - NADH
Robertsonian translocation and mosaicism
ADPKD

18. What metabolic rxns occur in the mitochondria
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
DNA
Vincritsine/vinblastine
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

19. Is there any requirement for homology in NHEJ
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1
Met - val - arg his
No - its non homologous
Cri du chat

20. What is chediak higashi
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
More than 1 codon may code for the same amino acid
DTMP
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy

21. hepatosplenomegaly - aseptic necrosis of femur - bone crisis - MACS that look like crumpled tissue paper

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22. What is the TX for pyruvate dehydrogenase deficiency
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Inhibits 50S peptidyltransferase
Comlex II

23. What is the energy source in the fed state right after a meal
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Glycolysis and aerobic respiration
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Essential fructosuria - fructokinase AR

24. What part of the pre mRNA contains the actual genetic information coding for protein
Exons
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Alanine
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent

25. How does cytosine become uracil
Deamination
Glycogen synthase
Griseofulvin
Glycine - aspartate - glutamine

26. What are cyclin - CDK complexes
FAP
Glutamate
Oxidized hemoglobin precipiated within RBCs
Must be both activated and inactivated for cell cycle to progress

27. Patients with chronic granulomatous disease are at increased risk of infection From which kind of organisms
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
GAA
Targets the proteins for lysosome
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais

28. what disease can cause pellagra
Specific glycosylases - AP endonuclease
Reads usual codon but inserts wrong AA
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Lacks glucose 6 phophatase

29. What does CATCH 22 stand for and What causes is...
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
One
3' end (with CCA)
Mucus secreting globlet cells and antibody secreting plasma cells

30. caf
Neurofibromatosis type 1 (von Recklinghausens disease)
Adds 2 carbon with the help of biotin
Protein kinase A
Arginine

31. What substances induce phosphofructokinase
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
AMP - fructose 2 -6 BP
Two

32. What are the water soluble vitamins - which ones are stored
Initiate chains
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Glutamine PRPP amidotransferase

33. What is the amino acid precuror for creatine - urea and nitric oxide
Dermatitis - glossitis - and diarrhea
Arginine
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

34. What is the activated carrier for Acyl
Coenzyme A - lipoamide
Dopa decarboxylase
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
Arg - lys - his - arg is most basic - has has no charge at body pH

35. What is the rate limiting enzyme in cholesterol synthesis
HVA
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Autosomal recessive diseases
HMG- CoA (HMG- CoA to mevalonate

36. What happens to oxaloacetate in alcholism
Specific glycosylases - AP endonuclease
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Abnormal protein folding - degradation before reaching cell surface
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity

37. What enzyme converts phenylalanine to tyrosin
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
Phenylalanine hydroxylase
Mental retardation - macro - orchidism - long face with large jaw - large everted ears - autism - and mitral valve prolapse
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

38. What are the two transgenic strategies in mice
DsRNA promotes degradation of target mRNA knocking down gene expression
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
P2 +2pq+ = 1

39. What collagen type is most frequently affected in ehlers danlos and What are common complications
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Orotic acid to UMP
MRNA
III - joint dislocation - anuerysms - organ rupture

40. What is a frame shift
Lacks glucose 6 phophatase
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
MRNA - tRNA
Ile - phe - thr - trp

41. What causes B12 def
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Neurons

42. What is proteasomal degredation
Initiate chains
X- linked recessive
Oral uridine administration
Attachment of ubiquitin to defective proteins tag them for breakdown

43. What do neurofilaments stain for
Neurons
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Wobble
Base + ribose + phosphate (3' -5') phosphodiester bond

44. Which type of chromatin is less condensed - transcriptionally active - sterically accesible
Euchromatin
Met - val - arg his
TTP
25OHD3

45. ADPKD is associated with What additional conditions
Schwann cells - lens - retina - kidneys
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Keep glutathione reduced so it can detoxify free radicals and peroxides
Polycystic liver disease - berry aneurysm - mitral valve prolapse

46. What happens in vit K def
Kidney - ears - eyes
Basement membrane or basal lamina
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx

47. What is a nonsense mutation
Silencers
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Change resulting in early stop codon

48. What converts limit dextran to glucose
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
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
HGPRT - defective purine salvage - excess uric acid production
Debranching enzyme

49. Which amino acids are elastin rich in
HVA
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Proline and glycine (non glycosylated forms)
Q -

50. What does the golgi assemble proteoglycans from
ATP - citrate
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Core proteins