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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. Give an example of a mitochondrial inherited disease
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Mutated dystrophin gene - less severe - adolescence
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
APRT + PRPP

2. what happens in acyl coa dehyrdogenase def
Activates LCAT
Inc dicarboxylic acids - dec in glucose and ketones
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol

3. What is codominance and give an example
Only processed RNA
Neither of 2 alleles is dominant - blood groups
Consesus sequenec of base pairs
After citruline

4. What are the products for glycolysis
ATP
RNA poly II
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage

5. What ribosomes do eukaryotes have
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
2 rings
Medial dorsal nucleus of thalamus - mamillary bodies
40 - 60 - 80

6. What are possilbe presentation for galactokinase def
Reads usual codon but inserts wrong AA
Fatty acid oxidation - acetyl - Coa production - TCA cycle - OXPHOS
SnRNPs
Failure to track objects or develop a social smile

7. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
DTMP
Intermediate filaments
Eu - methionine - pro - formyl - methionine
Hepatic glycogenolysis >> hepatic gluconeogenesis > adipose release of FFA

8. What is the activated carrier for aldehyddes
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Biotin
TTP
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

9. What does DNA poly III do?

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10. Where is fructose 1 -6 bisphosphatase found and What does it do
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Cleft palate - cardiac abnl - pregs test
Binds 50S - blocking translocation
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

11. How does cytosine become uracil
Exercise: inc NAD/NADH - inc ADP - inc Ca
Constitutive - random insertion of gene into mouse genome and conditional - targeted insertion or deletion of gene through homologous recombination with mouse gene
Base + ribose
Deamination

12. How do you diagnose CFTR
Provide a source of NADPH from an abundantly available glucose 6P - create ribose for nucleotide synthesis and glycolytic intermediates
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Inc Cl - in sweat
Base + ribose

13. What is the activated carrier for electrons
NADH - NADPH - FADH2
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Huntingtons
Locus heterogeneity - ocular albinism is x- linked recessive

14. What does vit E def cause
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
TTP
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)
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

15. Which anticancer drugs work on microtubules
Vincritsine/vinblastine
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Promotor - TATA box - and CAAT box - AT rich
AR

16. What does DNA poly I do?
Prokaryotic only - degrades RNA primer and fills in the gap with DNA
Dermatitis - glossitis - and diarrhea
Flank pain - hematuria - HTN - progressive renal failure
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate

17. protein malnutrition resulting in skin lesions - edema and liver malfxn
Creat a nick in the helix to relieave supercoils created during replication
Kwashiorkor - small child with swollen belly
CFTR gene - 7 - Phe 508
Exons

18. What activates the pyruvate dehydrogenase complex
Liver - ovaries - seminal vesicles
Exercise: inc NAD/NADH - inc ADP - inc Ca
Ribose 5- P to PRPP
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

19. What is the Name and fxn of vit B5
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Inc glucagon - inc cAMP - inc PKA

20. What happens in hyperammonemia
ATP and methionine
PMNs
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR

21. What does vit B3 def result in
Converted to THF - a coenzyme for one - carbon transfer/methylation reactions - important for synthesis of nitrogenous bases in DNA and RNA
Alanine
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

22. The pyruvate dehydorgenase complex serves In what reaction: reactants
Pyruvate - NAD+ - CoA
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
Galactitol - galactose appears in blood and urine - can cause infantile cataracta - AR
Disorder of aromatic amino acid metabolism

23. What does a northern blot use as its sample
RNA poly II
CGG
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
RNA

24. What enzyme does fructose metabolism bypass to reach glycolysis
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
PFK - rate limiting enzyme
Miscarriage - stillbirth - chromosomal imbalance (down - patau)

25. What is dominant negative mutation and give an example
P+q = 1
FISH
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding

26. What is NAD+ generally used for
Glycogen and FFA oxidation; glucose conserved for final sprinting
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Degredation of TG circulating in chylomicrons and VLDLs
Catabolic processes to carry reducing equivalents away as NADH

27. What is the TX for CF and What does it do
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
Connective tissue
Proline and glycine (non glycosylated forms)
Asp and Glu

28. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
Nonsense > missense > silent
Proline and glycine (non glycosylated forms)
9+2 arrangement of microtubules
Orotic acid to UMP

29. What is linkage disequilibrium
Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance - varies is different populations
Adds 2 carbon with the help of biotin
AR
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles

30. What part of the pre mRNA contains the actual genetic information coding for protein
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes
DNA
Exons
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

31. What does fomepizole do
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Unmethylated - newly synthesized - HNPCC
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
By inhibiting formation of the initiation complex and cause misreading of mRNA

32. A small proportion of Down syndrome is due to What two genetic events
Acetyl - CoA to malonyl - CoA (2C to 3C)
Alpha1 antitrypsin
Robertsonian translocation and mosaicism
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

33. What do B- complex vitamin deficiencies often result in
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Adds an inorganic phosphate onto substrate without using ATP
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Dermatitis - glossitis - and diarrhea

34. Of the four possible fates for pyruvate - which one can replenish TCA cycle or be used in gluconeogenesis
Glycogen synthase
Oxalacetate
Phenylketones in urine
Binds to LDL receptor - mediates VLDL secretion

35. What enzyme becomes essential in PKU
Hunters - iduronate sulfatase - heparan sulfate/dermatan sulfate - XR
Night blindness - dry skin
Inc melt - dec fluidity
Tyrosine

36. What are the findings in PKU
Malapsorption syndromes like sprue or CF or mineral oil intake
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Degredation of TG circulating in chylomicrons and VLDLs
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor

37. What are Heinz bodies
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination
Oxidized hemoglobin precipiated within RBCs
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA

38. Which carbon bears the triphosphate and the energy source for bond formation

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39. How do permanent cells grow and regenerate and What are examples of permanent cells
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Acetly- CoA - CO2 - NADH
No - its non homologous
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20

40. what disease can cause pellagra
Antioxidant - protects RBCs and membrances from free radical damage
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies
Glycolysis - fatty acid synthesis - HMP shunt - protein synthesis (RER) - steroid synthesis (SER)

41. Pts with albinism are at inc risk For what cancer
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Skin
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Fed

42. What happens do glycogen in skeletal muscle during exercise
Acetyl - CoA carboxylase (ACC)
Glycogenolysis to form glucose
Disorder of aromatic amino acid metabolism
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

43. What co - factors are required for the pyruvated dehydrogenase complex
Hydroxyurea - inhibits ribonucleotide reductase - 6 MP - blocks de novo purine synthesis - 5 FU inhibits thymidilate synthase - MTX - inhibits DHFR - Trimethroprin inhibits bacterial DHFR
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
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

44. What does DNA ligase do
Makes RNA primer on which DNA poly III can initiate replication
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Stop codon is recognized by release factor - and completed protein is released from ribosome
Seals.

45. Which anti breast cancer drugs work on micortubules
Paclitaxel
By inhibiting formation of the initiation complex and cause misreading of mRNA
Pseudomonas and s aureus
Acetyl - CoA

46. What 3 syndromes are associated with vit B1 def
Thymic - parathyroid and cardiac
Specific glycosylases - AP endonuclease
Wernicke - korsakoff - dry and wet beriberi
Cre - lox system

47. What feedback inhibits hexokinase
Elastase - inhibited by alpha1 antitrypsin
Glucose -6 phosphate
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

48. What are the functinos of vitamin A
B100
CAG - 4
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two

49. What enzyme converts adenine to AMP
Myeloperoxidase
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
APRT + PRPP
Met - val - arg his

50. What does a southern blot use as its sample
SAM
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
DNA
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step