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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 energy source for tRNA actication (charging)
Q -
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
ATP
Receptor tyrosine kinases - protein phosphatase - takes phosphate off glycogen phosphorylase kinase inactivating it

2. What does apoE do
Binds to LDL receptor - mediates VLDL secretion
Mediates extra remnant take up
Arg - lys - his - arg is most basic - has has no charge at body pH
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase

3. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
Foliage - small reserve in liver - eat green leaves
ATP hyrdolysis couple to energetically unfavorable rxns
Active secretion in lungs and GI - reabsorbs in skin
Type II

4. What does desmin stain for
P+q = 1
Muscle
MRNA - tRNA
The triphosphate bond

5. What does a pyruvate dehydrogenase deficiency lead to and What are the findings
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Carbomoyl phosphate synthetase II
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins

6. What does inc phenylalanine lead to...
Phosphorylation - glycosylation - hydroxylation
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Phenylketones in urine
Arg - lys - his - arg is most basic - has has no charge at body pH

7. in a 100 meter sprint Where does energy come from
Glycogenolysis to form glucose
Dec DNA - dec lymphos leads to SCID
Stored ATP - creatine phosphate - anaerobic glycolysis
Vit K antagonist

8. What ribosomes do prokaryotes have
Blood - bone marrown - amniotic fluid - placental tissue
Inc dicarboxylic acids - dec in glucose and ketones
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis
30 - 50 - 70

9. What is the TX for CF and What does it do
5' of the incoming nucleotide
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Targets the proteins for lysosome

10. trinucleotide repeat fo myotonic dystrophy
P+q = 1
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine
CTG
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

11. What happens on the oxidative arm of the HMP shunt and What is the key enzyme
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
Liver - also in kidney and gut epithelium
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
ADPKD

12. How is ATP used by the cell
Covalent cross - linking by lysyl oxidase to make collagen fibrils
ATP hyrdolysis couple to energetically unfavorable rxns
1 ring
Site of steroid synthesis and detoxification of drugs and poisons

13. What is the longest time of RNA and shortest
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Q -
MRNA - tRNA
HMP shunt

14. bilateral - massive enlargement of of kidneys due to multiple large cysts
ADPKD
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
Niacin - constituent of NAD and NADP - derived from tryptophan
No - its non homologous

15. What rxn does propionyl - CoA carboxylase catalyze
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Fed
1 -25 OH2 D3 = calcitriol
African Americans and Asians

16. What is the hardy weinberg allele prevalence
Degradation of TG remaining in IDL
P+q = 1
Phenylketones in urine
Nature and severity of phenotype vary from 1 individual to another - NF type 1

17. characterize x linked recessive
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
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

18. What does the golgi do to sugars in proteoglycans and of selected tyrosine on proteins
3' end (with CCA)
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
2pq
Sulfation

19. progressive neurodegeneration - developmental delay - cherry red spot on macula - lysosomes with onion skin - NO hepatosplenomegaly
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
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Heterochromatin = HighlyCondensed
Collagen

20. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
DNA
Consesus sequenec of base pairs

21. What lab value can distinguish orotic aciduria from ornithine transcarbamoylase def?
Unwinds DNA template at replcation fork
OTC has hyperammonemia - orotic aciduira does not
Purines= A - G pyrimidine = C - T (U)
MRNA

22. What is the most common urea cycle disorder and What is the mode of inheritance?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
AR disorder characterized by defective neutral amino acid transporte on renal and intestinal epith cells
Familial hypercholesterolemia - hyperlipidemia type IIA
Essential fructosuria - fructokinase AR

23. What is the fxn of vit E
Essential fructosuria - fructokinase AR
FAP
Antioxidant - protects RBCs and membrances from free radical damage
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive

24. What is the defect in fructose intolerance and What does it cause
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Lack of proper dietary therapy during pregnancy leading to microcephaly - mental retardation growth retardation - congenital heart defects
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene

25. What substances are uncouling agents
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
RRNA
2 -4 DNP - aspirin
Infection - free radicals generated by inflammatory response

26. Which RNA poly opens DNA at promotor site
Glycogen and FFA oxidation; glucose conserved for final sprinting
Malabsorption and steatorrhea (ADEK)
RNA poly II
Oligomycin

27. What is disulfiram used for
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Fasting
Griseofulvin
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses

28. What is the activated carrier for electrons
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)
By inhibiting formation of the initiation complex and cause misreading of mRNA
NADH - NADPH - FADH2

29. Type IV collagen
Neg to pos
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Basement membrane or basal lamina
Connective tissue

30. What does Citrate Is Krebs starting substrate for making oxaloacetate
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
MRNA - tRNA
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
32 - malate aspartate shuttle

31. What is chediak higashi
No - its non homologous
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Rb and p53

32. characterize autosomal recessive inheritance
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Arg and his inc in histones Which bind negatively charged DNA
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
RRNA

33. What substance accumulates in galactokinase def and What is the clinical picture
Alpha 1 -6 and alpha 1 -4
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
HGPRT - defective purine salvage - excess uric acid production
Inc intestinal absorption fo calcium and phosphate - inc bone resorption

34. What causes Marfan syndrome
Defect in fibrillin
Glycogenolysis to form glucose
B100
Unmethylated - newly synthesized - HNPCC

35. How many rings do purines have
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia
HMG- CoA (HMG- CoA to mevalonate
THFs
2 rings

36. What residues are hydroxylated in step 2 of collagen synthesis - and What does this require
Proline and lysine - vit C
Tuberous sclerosis
ADPKD
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes

37. What drugs can cause folate def
Transfers methyl units
Each codon specifies only 1 amino acid
Changed AA (convservative - new AA is similar in chemical structure)
Phenytoin - MTX - and sulfonamides

38. 90% of ADPKD cases are due to a mutation In what gene
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Infection - free radicals generated by inflammatory response
SnRNPs and other proteins
APKD1 on chromosome 16

39. What is the breakdown product of epi
Glutamine PRPP amidotransferase
Metanephrine
Malabsorption and steatorrhea (ADEK)
Promotor - TATA box - and CAAT box - AT rich

40. What is the RDE of de novo purine synthesis
Glutamine PRPP amidotransferase
Oxidative is irreversible
Carnitine acyltransferase I
Bind 30s subunit preventing attachment of aminoacyl - tRNA

41. What causes patau's syndrome and What is it
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
Stop codon is recognized by release factor - and completed protein is released from ribosome
Creat a nick in the helix to relieave supercoils created during replication
Phenylalanine

42. What order kinetics does EtOH dehydrogenase have
Zero
Two
B48 - AIV - CII - E
Enter G1 from G0 when stimulated - hepatocytes and lymphocytes

43. NADPH are used In what 4 things
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Pseudomonas and s aureus
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Phosphorylation - glycosylation - hydroxylation

44. What 3 amino acids are necessary for purine synthesis
Glycine - aspartate - glutamine
Neg to pos
ATP hyrdolysis couple to energetically unfavorable rxns
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus

45. characterize autosomal domint inheritance
Phenylalanine hydroxylase
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Foliage - small reserve in liver - eat green leaves

46. What enzyme converts adenine to AMP
Glycogen and FFA oxidation; glucose conserved for final sprinting
APRT + PRPP
Liver and leafy veggies
Glucose - 2Pi - 2ADP - 2NAD+

47. What two pathways is carbomoyl phosphate involved in - and what enzyme deficiency leads to a build of carbamoyl phosphate leading to what element in pyrimidine synthesis
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Wernicke - korsakoff - dry and wet beriberi
Microtubules
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

48. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Grows slowly - collapses quickly
Glycogen synthase
MRNA
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin

49. Describe the location and fxn of the Na/K ATPase
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Glycine
No

50. What are the teratogenic effects of vit A and What test must be ordered before starting a woman on isotreitinoin for severe acne
Cartilage - hyaline - vitreous body - nucleus pulposus
Cleft palate - cardiac abnl - pregs test
Malate - aspartate shuttle or the glycerol 3 phosphate shuttle
Neural tube