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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 are the results of pancreatic insuff in CF
Covalent cross - linking by lysyl oxidase to make collagen fibrils
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns
Scurvy - swollen gums - bruising - hemarthrosis - anemia - poor wound healing - weakened immune response
Malabsorption and steatorrhea (ADEK)

2. What tissue samples are used for karyotyping
HMG- CoA reductase
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism
Blood - bone marrown - amniotic fluid - placental tissue
Essential fructosuria - fructokinase AR

3. What does commaless - nonoverlapping genetic code refer to...
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Same as sprint + OXPHOS
Ca/calmodulin in muscle to coordinate with muscle activity
Read from a fixed starting point as a continuous sequence of bases

4. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Pyruvate to oxaloacetate (3C to 4C)
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Hypoxanthine to xanthing and xanthine to uric acid
Von gierkes - glucose 6 phosphatase

5. What happens in a B12 def
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
APKD1 on chromosome 16
Pyruvate - NAD+ - CoA

6. Why can't even chain fatty acids produce new glucose
Prevent strands from reannealing
CG- 3 > AT-2 - More CG content - melting point goes up
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
They yield only acetyl - CoA equivalents

7. what disease can cause pellagra
ATP
Ketone - methyl
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision

8. What is kartageners syndrome
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Inc CPK and muscle biopsy
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

9. 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
Hypoglycemia
Activates LCAT
Wobble
Creat a nick in the helix to relieave supercoils created during replication

10. What two rxns in in glycolysis require ATP
SAM
Sucrose = glucose + fructose - lactose = glucose + galactose
Males are infertile due to bilateral absence of vas deferens
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

11. Why enzyme breaks down elastin and what enzyme inhibits it
B48 - AIV - CII - E
Microtubules
Elastase - inhibited by alpha1 antitrypsin
Orotic acid to UMP

12. Where is vit B12 found
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Comlex II
Blood - bone marrown - amniotic fluid - placental tissue

13. What is the source of energy in the fasting state between meals
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
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA
Heterochromatin = HighlyCondensed
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive

14. Very Poor Carbohydrate Metabolism stands for 4 of the glycogen storage diseases - What are thy

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15. In eukaryotes - What does RNA poly II make
Inc vit B6
Essential for the activity of over 100+ enzymes - important in the formatio of zinc fingers -
MRNA
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

16. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
SnRNPs and other proteins
Same AA - often base change in 3rd position of codon (tRNA wobble)
Acetyl - CoA
Arginine

17. What neuroanatomical strutures are injured in wernicke - korsakoff
UGA - UAA and UAG
THFs
Medial dorsal nucleus of thalamus - mamillary bodies
MEN - 2A and 2B with ret gene

18. What is the RDE of glycogen synthesis
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Glycogen synthase
NAD+

19. What are bite cells and when do you see them
Result from phagocytic removal of heinz bodies my macs - G6PD def
FISH
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Disease

20. What causes Marfan syndrome
Defect in fibrillin
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two

21. What are the mRNA stop codons
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Familial hypercholesterolemia - hyperlipidemia type IIA
Transmitted only through mother - all offspring of affected females may show signs of disease
UGA - UAA and UAG

22. What are the results of unbalanced translocation
LCAT (lecithin cholesterol acyltransferase)
Prevent strands from reannealing
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

23. What is the energy source in the fed state right after a meal
Glycolysis and aerobic respiration
Fructose via sorbitol dehydrogenase - inc sorbitol leading to osmotic damage as in cataracts - retinopathy - peripheral neuropathy as in diabetes
The triphosphate bond
Carbomoyl phosphate synthetase II

24. Which anticancer drugs work on microtubules
Alpha 1 -4 glucosidase
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Vincritsine/vinblastine
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast

25. What is the fxn of vit E
Aminoacyl - tRNA binds A site - ribosomal rRNA catalyzes peptide bond formation - transfers growing peptide to AA in A site - ribosome advances 3 nucTIDE toward 3' end of RNA - moving peptidyl RNA to P side
Q -
Antioxidant - protects RBCs and membrances from free radical damage
Polyneuritis - symmetrical muscle wasting

26. What happens in vit D excess
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
FISH
Alpha1 antitrypsin

27. Is there any requirement for homology in NHEJ
Foliage - small reserve in liver - eat green leaves
Oral uridine administration
Ile - phe - thr - trp
No - its non homologous

28. What enzyme converts glucose 1 p to UDP glucose
CTG
Type II
NAD+
UDP glucose pyrophosphorylase

29. How do odd chain fatty acids participate in gluconeogenesis
Glutamate
Degradation of TG remaining in IDL
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
LPL def - or altered apoCII - elevated TG and cholesterol - causes pancreatitis - hepatosplenomegaly and eruptive/pruritic xannthomas - no risk of atherosclerosis

30. How does patients present with ADPKD
Hyperlipidemia
Flank pain - hematuria - HTN - progressive renal failure
Cartilage - hyaline - vitreous body - nucleus pulposus
Liver and leafy veggies

31. What two amino acids are required druing periods of growth and why
Arg and his inc in histones Which bind negatively charged DNA
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Liver - also in kidney and gut epithelium

32. Which phase of the HMP shunt is reversible and Which is irreversible
Acetly- CoA - CO2 - NADH
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Oxidative is irreversible
IDL

33. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
CAG - 4
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Malabsorption and steatorrhea (ADEK)
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus

34. What is the complication of cystinuria
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Inc CPK and muscle biopsy
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)

35. What shuttle is used in fatty acid degredation and What does it move and From where to where
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Carnitine shuttle - acyl - coa from cyto to mito
Adenosine to inosine
Adds 2 carbon with the help of biotin

36. In eukaryotes - What does RNA poly III make
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
TRNA
Muscle
Glycolysis and aerobic respiration

37. 1 g of protein or cabrohydrate = ?kcal
OTC has hyperammonemia - orotic aciduira does not
Free ribosomes
FAP
Four

38. Where is vit A found in the diet
Liver and leafy veggies
Carnitine acyltransferase I
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
HVA

39. What happens in vit K def
HMG- CoA reductase
Neonatal hemorrhage with inc PT and PTT - but nl bleeding time - can also occur after prolonged use of broad spectrum Abx
Cytosol
Unmethylated - newly synthesized - HNPCC

40. What is the amino acid precuror for creatine - urea and nitric oxide
Inc dicarboxylic acids - dec in glucose and ketones
Robertsonian translocation and mosaicism
Arginine
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)

41. What does apoE do
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease
Inc melt - dec fluidity
Mediates extra remnant take up
Binds to LDL receptor - mediates VLDL secretion

42. What are the products for glycolysis
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Modifies N- oligosaccharides

43. When are glycogen reserves depleted
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
Removal of N or C termal propeptides from zymogens to generate mature proteins
After day 1
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

44. What does cytokeratin stain for
Epithelial cells
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Dopamine beta hydroxylase
Purines= A - G pyrimidine = C - T (U)

45. congenital microdeletion of long arm of chromosoe 7 with findings of elfin facies - mental retardation - hypercalcemia - well developed verbal skills - extreme friendliness with strangers - cardiovascular problems
Marasmus - muscle wasting
Williams syndrome
Terminal regions - tropocollagen
Arginine

46. Which aspect of the spliceosome do patients with lupus make antibodies against
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
SnRNPs
Mediates chylomicron secretion

47. What activates the pyruvate dehydrogenase complex
Reads usual codon but inserts wrong AA
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Exercise: inc NAD/NADH - inc ADP - inc Ca
X- linked recessive

48. What is the treatment for orotic aciduria
Dopamine beta hydroxylase
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Oral uridine administration
30 - 50 - 70

49. What is the RDE of de novo pyrimidine synthesis
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
Carbomoyl phosphate synthetase II
CTG
Bind 30s subunit preventing attachment of aminoacyl - tRNA

50. How do labile celss grow and regenerate and What are examples
Marasmus - muscle wasting
Orotate precursor - with PRPP added later
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Same as sprint + OXPHOS