biochem AA pro

  1. aa characters 3
    • s config (except cysteine which is R)
    • alpha C is chiral except glycine
    • optically active
  2. in eukaryotic cells, AA are L and left of fischer projection
  3. nonpolar and non aromatic 7 (single bonds all around even 1 ring)
    • glycine
    • alanine
    • valine
    • isoleucine
    • leucine
    • methionine
    • proline
    • *get all violet incense,lets make perfume*
  4. aromatic side chains 3 (aromatic rings)
    • tryptophan
    • phenylalanine
    • tyrosine
    • *turkey produces tiredness*
  5. polar side chains 5 (have nh2, oh, or sh)
    • serine
    • threonine
    • aspragine
    • glutamine
    • cysteine
    • *screw the artic, get coats*
  6. negative side chains 2
    • aspartate
    • glutamate
    • *all girls*
  7. positive side chains
    • arginine
    • lysine
    • histidine
    • *all hearts love*
  8. 2 facts of behaviors for AA
    • ionizable groups gain protons under acidic conditions and lose protons under basic
    • if PHis ph>pka species will be deprotonated
  9. AA have 2 groups that can be deprotonated, COOH and NH2, the SC id ionizable. If it is already protonated then nothing will happen
  10. at neutral pH, you will only have depro version AA
    • NH2 will b the same while COOH becomes COO-
    • below pka of AA, NH2 will be protonated as its conjugate acid
  11. example of titration curve
    • middle points of the curve are when ph is close to Pka and it creates a buffer
    • at a low ph the AA was fine, and as more basic was added, cooh becomes deprotonated, when the equivalent is reached, the solution will be neutral
    • as more basic is added,NH3 becomes depro
    • cooh is first to change because its ph is 2 and NH3 is 9-10
  12. AA with ASC will have pi values below 6
    AA with BSC will have pi values above 6
  13. extra step in AA side chains of glutamic acid and lysine
    they are in a positive state, depro in main carboxyl group, then it becomes neutral before being deprotonated again to becomes negative
  14. structures of proteins
    • primary - formation of pep bonds to AA
    • secondary - alpha and beta pleated sheets occur due to intramolecular H bonding between nearby AA
    • tertiary - creation of hydrophobic or philic side chains though a 3d structure
  15. alpha helices 3
    • pep chain coils around central axis
    • intramolecular H bondingbetween carbonyl oxy atom and amide H
  16. beta helices
    • II or T lie along each to form rows
    • IMHB between carbonyl oxy on one chain and amide H in an adjacent chain
  17. In teriary structure, phobic SC move inside of pro while philic get pulled by phobic to stabilize pro from inside
    surface of AA have polar or chargd (philic) r groups
  18. structure of 3d of tert is determined by H bonds and AB rxns between AA and charged SC to create disulfide bonds(salt bridges)
  19. Hemoglobin and immunoglobins have 4 subunits in which can bind one molecule of oxygen
  20. a hydrophob SC is placed in an aqe solution w/ solvation layer
    • the h2o molecules in the solvation layer cannot form h bonds so they can arrange into specifics to maximize h bond
    • the hydophil residues in the aqe solutions gives h2o positioning
  21. amphoteric species
    either accept or donate a pro
  22. zitterions
    molecules with a - & + charge that is electrically neutral
  23. polyprotic acid
    an acid that can donate more than one proton
  24. the conc of enzyme and substrate effct how quickly a reaction will occur, the higher the amount of enzyme and sub the reaction is saturated, meaning enzyme is working at max velocity **michaelis-menten equation**
    • e+s=ES=E+p
    • km is a constant to mean affinity of the enz for its sub
  25. example of km
    • increae km has decrease affin for its sub b/c it needs increase sub
    • when KM = conc of sub, 1/2 of the AE sites are full
  26. cooperative enzymes have multiple subunits
    • low affinity tense state T have decreased affin
    • high affinity relaxed state R have increased affin
    • binding of a sub causes T to R
    • loss of binding causes R to T and causes more substrate to disassociate from the subunit
  27. 4 type of inhibition
    • competitive
    • noncompetitive
    • mixed
    • uncompetitive
  28. reversal inhibition
    add more sub to increase sub to inhibit ratio, enzyme will want to bind to sub instead of inhibit
  29. competitive inhibition and reversal
    • inhibitor binds to the site and sub can not bind to it
    • **km will increase do to inhibit b/c it decreases affin
  30. noncompetitive inhibitors and reversal
    • causes enzyme config change so no sub can bind
    • it decreases Vma b/c less enzymes
    • increases km b/c affin is still increased
  31. Vmax meaning
    velocity at which the rate of the rxn is occurring
  32. mixed inhibition
    • inhibitors can bind to enzyme of enzyme-sub complez
    • can increase km inhibit binding to enzyme
    • decrease km inhibiting binding to e-s complex
  33. uncompetitive inhibitors
    • only bind to E/s complex and locks them in place
    • cannot be removed from each other
    • lowers km and increases affinity
Card Set
biochem AA pro
biochem mcat