MCAT Biochemistry

  1. amino acid
    • Has an amino group and an carboxly group 
    • -Nh2 -COOH
    • 20 proteinogenic
  2. Codon
    A sequence of 3 nucleotide that form a unit of genetic code in DNA or RNa molecules.
  3. Urea cycle
    The metabolic process by which the body expels excess nitrogen.
  4. sterogenic/ chiral
    haveing four different groups attached to it.
  5. Glycine
    h is the fr group and it is the only achiral amino acids
  6. Eukaryotes
    • all amino acids in eurklaryotes like you and I are like you and I are L-amino aids. L for living.
    • Thus the aminogroup is drawn on the left for a fisher projection
  7. Cysteine
    This is the only L-amino acid with an R absolute configuration
  8. aliphatic
    non aromatic. can be a ring structure but cannot have alternating double bonds like the typical aromatic ring
  9. Proline
    • kinky amino acid 
    • forms a five-membered ring with the amino group
    • limited flexibility and which limits where it can appear in a protein
  10. pKa
    • The ph at which half of the the molecules in a species is protonated and the other half is deprotonated
    • [HA]=[A-]
  11. pH and pke relationship
    • when the ph is lower than the pKa the species tend to to be protanted for the majority 
    • and vice versa
  12. ka
    • acid ionization constant 
    • this measures the strength of an acid
  13. catalytic triad found in chympotrypsin
    • Histidine 
    • Aspartic acid
    • and serine
  14. amphoteric
    having the characteristics of both an acid and a base
  15. alliphatic
    • like a detergent:
    • has both hydrophobic and hydrophillic groups.
  16. amino acids in different pH environment
    • ionizable groups tend to be protonated in acid environment and deprotonated in basic environments.
    • thus low ph means that the ionizable group is protonated and at high pH it is deprotonated.
Card Set
MCAT Biochemistry