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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 function of biotin
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
UGA - UAA and UAG
Fasting
Acetoacetate and beta hydroxybutyrate

2. Acetyl - CoA carboxylase catalyzes what rxn
Protein
APRT + PRPP
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects
Acetyl - CoA to malonyl - CoA (2C to 3C)

3. progressive neurodegeneration - hepatosplenomegaly - cherry red spot on macula - foam cells
Neimann - pick - sphingomyelinase - sphingomyelin - AR
Oxidative is irreversible
Uses ATP to add high energy phophate group onto substrate
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

4. What is the most abundant type of RNA
RRNA
Binds to LDL receptor - mediates VLDL secretion
Isocitrate dehydrogenase
Conversion of NE to epi

5. peripheral neuropathy of hands/feet - angiokeratomas - CV/renal disease - dz - def enzyme - acc substrate - inherit
Rb and p53
Lysine and arginine
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Fabrys - alpha galactosidase A - ceramide trihexoside - XR

6. In eukaryotes - What does RNA poly III make
Core proteins
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
TRNA
Glycogen phosphorylase

7. For eukaryotes - Where does replication begin?
Hereditary spherocytosis
In ER - glucose 6- P to glucose
Consesus sequenec of base pairs
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)

8. What happens in hyperammonemia
B48 - AIV - CII - E
25OHD3
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22

9. protein malnutrition resulting in skin lesions - edema and liver malfxn
Polycystic liver disease - berry aneurysm - mitral valve prolapse
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Ile - phe - thr - trp
Kwashiorkor - small child with swollen belly

10. What happens in a B12 def
Vit K antagonist
APKD1 on chromosome 16
Mucus secreting globlet cells and antibody secreting plasma cells
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible

11. What kind of RNA is transported out of the nucleus
The triphosphate bond
Infection - free radicals generated by inflammatory response
Only processed RNA
Autosomal recessive diseases

12. Describe the replication fork
Sulfation
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Peroxide
Carbomoyl phosphate synthetase I

13. What is the target of the 3' hydroxyl attack
The triphosphate bond
Locus heterogeneity - ocular albinism is x- linked recessive
APC on chromosome 5
Catabolic processes to carry reducing equivalents away as NADH

14. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Microarrays
LCAT (lecithin cholesterol acyltransferase)
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)

15. What causes biotin def
Antibiotic use or excessive ingestion of raw eggs
Karyotyping
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
FAP

16. What is locus heterogeneity and give an example
1 -25 OH2 D3 = calcitriol
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Inc CPK and muscle biopsy
Mutations at different loci can produce the same phenotype - marfans - MEN 2B - homocystinuria; all cause marfinoid habitus - also albinism

17. What are the water soluble vitamins - which ones are stored
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Cartilage - hyaline - vitreous body - nucleus pulposus
Inc vit B6
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)

18. How many rings do pyrimidines have
Via 1 proprionyl - CoA which can enter the TCA as succinyl - CoA and undergo gluconeogenesis
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
1 ring
Glycogen phosphorylase

19. What happens with wet beriberi
Proline and lysine - vit C
Biotin
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
High output cardiac failure - dilated cardiomyopathy - edema

20. The pyruvate dehydrogenase complex serves In what reaction: products
Schilling test
NF2 on chromosome 22
Acetly- CoA - CO2 - NADH
Neg to pos

21. What is the purpose of the HMP shunt
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
HMP shunt
Inhibits RNA polymerase II - found in death cap mushrooms
Palate - facial and cardiac defects

22. Who typically has lactase def
African Americans and Asians
Blood - bone marrown - amniotic fluid - placental tissue
III - joint dislocation - anuerysms - organ rupture
Rb and p53

23. cardiomegaly - systemic findings leading to early death - dz and enzyme

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24. Type I collagen
After citruline
Modifies N- oligosaccharides
30 - glycerol -3- phosphate shuttle
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

25. What is the wernicke - korsakoff clinical picture
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
B100

26. What are the 2 distinct phases of the HMP shunt and How many ATP are used and produced
Coenzyme A - lipoamide
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light
Oxidative and nonoxidative - no ATP produced or used
Chronic granulomatous disease - no respiatory burst - no formatino of ROS

27. Broadly - What can cause fat - soluble vitamin deficiencies
Malapsorption syndromes like sprue or CF or mineral oil intake
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
DsRNA promotes degradation of target mRNA knocking down gene expression
Dec methionine - inc cystiene - inc B12/folate

28. What enzyme converts adenine to AMP
APRT + PRPP
Glutamate
Q -
UGA - UAA and UAG

29. What does acetyl - CoA become before becoming palmitate
Glutamine PRPP amidotransferase
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Phenylketones in urine

30. What collagen type is most frequently affected in ehlers danlos and What are common complications
Propionyl - CoA to methylmalonyl - CoA (3C to 4C)
Catalase positive (catalase neg produce H2O2 the cell can use) like S. aureus or aspergillus
III - joint dislocation - anuerysms - organ rupture
Oligomycin

31. What trinucleotide repeat in Huntingtons and what chromosome is it found on...
Proline and lysine - vit C
Transmitted through both parents - affected mother may have affected children - affected father will have affected children
CAG - 4
FMR1 gene - methylation - associated with chromosomal breakage

32. RNA poly can't proofread - but What can it do
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
Initiate chains
Unmethylated - newly synthesized - HNPCC
Microtubules

33. What apolipoprotein is on LDL
Glutamate
Phosphorylation - glycosylation - hydroxylation
Fibrofatty replacement of muscle - cardiac myopathy
B100

34. Where does gluconeogenesis primarily happen and What are other sites where the enzymes are located
Base + ribose + phosphate (3' -5') phosphodiester bond
Liver - also in kidney and gut epithelium
Tyrosine
Asp and Glu

35. What bone disorder has x linked dominant inheritance
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
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
Reads usual codon but inserts wrong AA

36. How are the many staggered tropocollagen molecules reinforced
Covalent cross - linking by lysyl oxidase to make collagen fibrils
Removal of N or C termal propeptides from zymogens to generate mature proteins
Only processed RNA
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

37. What is the activated carrier for methyl groups
SAM
Same AA - often base change in 3rd position of codon (tRNA wobble)
TTP
Unmethylated - newly synthesized - HNPCC

38. What are the names and sources of the two types of vit D found in nature
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Oligomycin
Targets the proteins for lysosome
Accelearted muscle breakdown

39. What can excess vit B3 cause
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Glycolysis and aerobic respiration
Facial flushing
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis

40. What neuroanatomical strutures are injured in wernicke - korsakoff
Medial dorsal nucleus of thalamus - mamillary bodies
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
NADPH

41. What are the fat soluble vitamins and What does their absorption depend on...
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Griseofulvin
Unwinds DNA template at replcation fork
Hypoxanthine to xanthing and xanthine to uric acid

42. What are the glucogenic/ketogenic amino acids
Skin
Ile - phe - thr - trp
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Semiconservative - continuous and discontinuous strands (okazaki fragments)

43. What is a missense mutation
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Changed AA (convservative - new AA is similar in chemical structure)
Phenylketones in urine
Rotenone - CN- - antimycin A - CO

44. What enzyme degrades a small amount of glycogen in lysosomes
4 under the floor
ATP
Alpha 1 -4 glucosidase
AMP - fructose 2 -6 BP

45. What is the energy source for translocation
Stored ATP - creatine phosphate - anaerobic glycolysis
Skin
GTP
Coenzyme A - lipoamide

46. What enzyme converts phenylalanine to tyrosin
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Mediates chylomicron secretion
Phenylalanine hydroxylase
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

47. 1 g of protein or cabrohydrate = ?kcal
Four
Diphyllobothrium latum
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Alpha 1 -4 glucosidase

48. Of the four possible fates for pyruvate - which ends anaerobic glycolysis as in RBCs - leukocytes - kidney medulla - lens - testes and cornea
Rotenone - CN- - antimycin A - CO
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Lactate
More than 1 codon may code for the same amino acid

49. What does Alports syndrome cause and why
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
1 kind with multiple subunits
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
Nucleotide excision repair - xeroderma pigmentosum; unable to repair thymidine dimers caused by UV light

50. Where is fructose 1 -6 bisphosphatase found and What does it do
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision