Biochemistry

Biochemistry

1. Amino acids and proteins

   • Role of amino acids in cells
     • Catalysis of reactions
     • Structural proteins
     • Histones:control genetic info
     • Transport systems
     • Interactions with sugar
     • Receptors
   • Structure
     • Chiral
       • Non-superimposing mirror images
       • aa always L form
     • 4 main groups
       • Hydrophobic aa with non-polar R group
       • Polar aa with neutral R group-uneven distribution of charge
       • +ve charged aa with+veR group at physiological pH
       • -ve aa with-ve R group at physiological pH
   • Nomenclature
     • 3 letter abbreviation
     • normally end in -ine
   • Zwitterions
   • Peptide bond formation
     • Condensation reaction
       • sequence has direction
     • Hydrolysis breaks bond
     • geometric isomers of bond
       • Cis-same side
         • Proline
       • Trans-opposite sides
         • Most aa-less steric clashes
   • Charged R groups
     • Some aa have basic(+) charge
     • Some have acidic (-) charge
   • Aromatic side chains
     • Absorb strongly at 280nm)
   • pKa
     • Effected by factor
       • Temperature
       • Ionic strength
       • Micro environment

2. Bond lengths

   • Chiral C-C carboxyl:1.51A
   • N to Chiral C:1.45A
   • C-O carboxyl:1.24 A
   • Peptide bond:1.32A
   • N-H a group:1A

3. Chemistry

   • Element, molecule, atom and compound definitions
   • Periodic table
     • Increasing atomic no.
     • Groups and periods-similar properties
   • RAM=sum of(Mrx%)/100
   • Hydrogen
     • Absorption spectrum
       • 4 district absorptions=specific quantity of E needed to reach excited state
   • Bohr's model of H atom
     • Problems:electrons should produce magnetic field=electrons spin off+ decrease E
       • All r values allowed
     • Restraints on system
       • r=kn^2 k=constant
         • Energy levels
           • greater n=closer energy levels
           • E confined to orbitals
           • s orbital
             • Spherical+symmetrical
           • P orbitals
             • 3:px,py,pz
               • axis
             • identical
           • d orbitals
             • 5:dz^2,dx^2-y^2,dxy,dxz,dyz
             • complicated
           • f orbitals
             • 7
             • very complicated shape
           • Fill from lowest E level
             • max 2 e- in each orbital
   • Schrodinger
     • For non H systems
     • wave-partial duality
     • solution=wavefunction=p of electron around nucleus
   • Bonding
     • Ionic bond
     • Covalent bond
     • electronegativity
       • >1.7=ionic
     • bonding+anti-bonding orbitals
       • in phase=bonding
       • out of phase=anti-bonding
     • Bond order
       • e bonding-e anti bonding
     • MO energy diagrams
   • Organic chemistry
     • Chemistry compounds of carbon
       • Catenate-from chain of C atoms
       • Form strong bond with itself
       • Large range of complexity
       • 1s2s2p2
         • Without hybridisation-only 2 bonds
     • Hybridisation
       • sp3= single bond
         • 1s+4xsp3 hybridised orbital-all have 1 electron
           • 4 bonds
           • Requires around 400kjmol-1
             • Energy made by bond form
           • sp3 orbitals can overlap with H s orbital
             • form sigma bond
         • Tetrahedral
       • sp2=c--c double bond
         • 1s2+3xsp2 hybridised+ unhybridised 2p orbital
           • similar shape orbital to sp3
           • Trigonal=120 degrees
           • 1xPi and 1xsigma
       • sp=c-c triple bond
         • linear
         • 1s2+2xsp hybridised+2xunhybridised
         • similar orbital shape to sp3

4. kinetics

5. Protein structure

6. Allosteric enzymes and inbitors

   • Competitive
     • Similar shape to substrate-compete for a site
     • Meet at y axis
     • KI=(E)(I)/(EI)
     • a=1+(I)/KI
   • uncompetitive
     • a'=1=(I)/KIS
     • KIS=(E)(IS)/(EIS)
     • Parallel lines-don't intercept
     • Inhibitor binds to ES
   • Mixed

7. functional groups and isomer

Bilder und Dateien der Mindmap