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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 does universal genetic code refer to and What are some exception
ATP
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
EtOH dehydrogenase and acetaldehyde dehydrogenase

2. 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
Protective against malaria
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
Chronic granulomatous disease - no respiatory burst - no formatino of ROS

3. What is locus heterogeneity and give an example
Adenosine to inosine
Failure to track objects or develop a social smile
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism

4. What is the Name and function of vit B1
Gamma carboxylation of glutamic acid residues on various proteins concerned with blood clotting - synthesized in intestinal flora
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
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

5. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Williams syndrome
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Biotin
ADPKD

6. What sugar is sorbitol converted to and via what enzyme - and What can happen in cells lacking this enzyme
Reads usual codon but inserts wrong AA
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates

7. What lab procedure is used to amplify desired fragment of DNA and What are the 3 steps
PCR - denaturation - annealing - elongation
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Inhibit DNA gyrase specific for prokaryotic topoisomerase
Phosphorylation - glycosylation - hydroxylation

8. caf
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Peroxide
Neurofibromatosis type 1 (von Recklinghausens disease)
PCR - denaturation - annealing - elongation

9. What substance in egg whites binds biotin
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Avidin

10. What catacholamine step is SAM required for
17 - 17 letters in von Recklinghausen
Conversion of NE to epi
Orotic acid to UMP
Ile - phe - thr - trp

11. What shape does the RNA generate during splicing and why?
Dermatitis - alopecia - enteritis
Lariat shape in order and remove intron precisely and join 2 exons
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

12. What does the primary transcript combine with to form the spliceosome
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
SnRNPs and other proteins
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
DNA

13. What tissues have both enzymes of sorbitol metabolism
Liver - ovaries - seminal vesicles
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
Same AA - often base change in 3rd position of codon (tRNA wobble)
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step

14. What does hartnups disease cause
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
2 rings
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra

15. What is the most abundant type of RNA
RRNA
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Removal of N or C termal propeptides from zymogens to generate mature proteins
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)

16. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
ATP and methionine
Marfans
B-100 - CII and E

17. What is the limiting reagent in EtOH metabolism
Unwinds DNA template at replcation fork
NAD+
Adds an inorganic phosphate onto substrate without using ATP
Nonsense > missense > silent

18. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
TTP
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
Assistance of upper extremities to stand up

19. what disease can cause pellagra
B12 and folate
Flagella - cilia - mitotic spindles
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
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

20. What does glycosylation of pro alpha chian yield and What is the structure
Procollagen - triple helix of 3 alpha collagen chains
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Rotenone - CN- - antimycin A - CO
Hypoglycemia

21. What does a decrease in decrease in NADPH lead to and why
Pseudomonas and s aureus
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Semiconservative - continuous and discontinuous strands (okazaki fragments)
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)

22. How doe NADH electrons from glycolysis and the TCA cycle enter the mitochondiria
Protective against malaria
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin

23. What causes biotin def
Antibiotic use or excessive ingestion of raw eggs
Cori's - debranching enzyme alpha 1 -6 glucosidase - gluconeogenesis intact
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Nonsense > missense > silent

24. What does a kinase do
75 to 90 - cloverleaf
Uses ATP to add high energy phophate group onto substrate
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

25. What happens to glycogen in the liver
Specific glycosylases - AP endonuclease
Robertsonian translocation and mosaicism
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
Supply sufficient glucose to brain and RBCs and to preserve protein

26. What leads to the deletion of the dystrophin gene in duchenne's muscular dystrophy
Marasmus - muscle wasting
Disease
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
X linked frame shif mutation

27. What are the water soluble vitamins - which ones are stored
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Phenylethamolamine N methyl transferase
Wobble
Vincritsine/vinblastine

28. What is the Name and fxn of vit B12
Four
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

29. What does SAM do
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin
Transfers methyl units
Thymic - parathyroid and cardiac
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

30. What is the amino acid precuros for niacin and serotonin/melatonin
Glycogenolysis to form glucose
Tryptophan
SNP
Epithelial cells

31. Which aspect of the spliceosome do patients with lupus make antibodies against
4 under the floor
SnRNPs
30 - glycerol -3- phosphate shuttle
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood

32. protein malnutrition resulting in skin lesions - edema and liver malfxn
APKD1 on chromosome 16
Kwashiorkor - small child with swollen belly
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it
Malonyl coa

33. What is the function of Zinc
Same AA - often base change in 3rd position of codon (tRNA wobble)
Fasting
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Degradation of TG remaining in IDL

34. characterize x linked recessive
VLDL
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
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
UGA - UAA and UAG

35. In the chromatin structure - which histones form the octamer - and which ties the nucleosome beads together in a string?
Octamer = 2 sets of H2A - H2B - H3 - H4 - tie =H1
PCR - denaturation - annealing - elongation
Proton gradient
Failure to track objects or develop a social smile

36. Who typically has lactase def
African Americans and Asians
Met - val - arg his
Karyotyping
Base + ribose

37. Formed and degradation of VLDL - delivers TGs and cholesterol to liver where they are degraded to LDL
NADPH
IDL
RRNA
P+q = 1

38. Accurate base pairing is required only in the first two nucleotide positions of an mRNA codon - so conds differeing in the 3rd position may code for the same tRNA/AA due to degenerate genetic code
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Familial hypercholesterolemia - hyperlipidemia type IIA
N to C
Wobble

39. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Inc insulin - dec cAMP - dec PKA
NF2 on chromosome 22
Liver - also in kidney and gut epithelium
Phenylalanine hydroxylase

40. What defects characterize DiGeorge syndrome
G6PD
Degradation of TG stored in adipocytes
Thymic - parathyroid and cardiac
LDL

41. Type II cartilage
Exons
CarTWOlage
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

42. What is the RER called in neurons and What is made there
Sulfation
Nissl body - enzyme and NTs
Glucose - 2Pi - 2ADP - 2NAD+
Supply sufficient glucose to brain and RBCs and to preserve protein

43. What does cytokeratin stain for
Epithelial cells
Assistance of upper extremities to stand up
B6
Targets the proteins for lysosome

44. Describe the location and fxn of the Na/K ATPase
Ribos first then deoxyribos with ribonucleotide reductase
Williams syndrome
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Dermatitis - glossitis - and diarrhea

45. What test is used for B12 def
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
Schilling test
Stored ATP - creatine phosphate - anaerobic glycolysis
Wobble

46. What is the defect in fructose intolerance and What does it cause
Alpha1 antitrypsin
DTMP
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Diphyllobothrium latum

47. Describe the replication fork
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Tuberous sclerosis
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Blood - bone marrown - amniotic fluid - placental tissue

48. Which amino acids are elastin rich in
Exercise: inc NAD/NADH - inc ADP - inc Ca
Basement membrane or basal lamina
Proline and glycine (non glycosylated forms)
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year

49. Fluorescent DNA or RNA probe binds to specific gene of interest - used for specific localization of genes and direct visualization of anomalies - like microdeletions - at molecular level
40 - 60 - 80
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
FISH
Prokaryotic only - degrades RNA primer and fills in the gap with DNA

50. What tissues have only aldose reductase
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
IDL
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Schwann cells - lens - retina - kidneys