L-alpha-Amino acids

L-alpha-Amino acids

1. Functions

   • Nerve transmission
   • Biosynthesis
     • Purines
     • Pyrimidines
     • Porphyrins
     • Urea
     • Proteins
       • They just need 20 types of amino acids
         • Every amino acid is encoded by...
           • Codons
             • They're nucleotide triplets of RNA
         • Hydrophilics
           • Arginine, asparagine, aspartic acid, cysteine, glutamin acid, glutamine, glycine, histidine, lysine, serine, threonine
         • Hydrophobic
           • Alaline, isoleucine, leucine, methionine, phenylalanine, proline, trypthophan, tyrosine, valine
         • They could be modified
           • Post-translational modification
             • Methhylation, formylatio, phosphorylation, etc

2. Charge

   • Aqueous solution
     • Amino Group: NH3+
     • Carboxile group: COO-
     • Zwitterion
       • Equal numbre of positive and negative charges
         • Present in aqueous solution as blood and most tissues

3. Proteins

   • Structures
     • Primary
       • Amino acids are linked together by peptide bonds
         • Amino acids present in peptides are called aminoacyl residues
     • Secondary
       • Aminoacyl residues adopt similar phi and psi angles
         • Alpha Helix
           • Equal amount about each phi angle (-57°) and psi angle (-47°)
             • The R groups of each aminoacyl residue face outward
               • There are hydrogens bonds formed between the oxygen of the peptide bond carbonyl and the hydrogen atom of the peptide bond nitrogen of the fourth residue down the polypeptide
         • Beta Sheet
           • Form a zig-zag or pleated pattern in which the R groups of the residuos project in opposite directions
             • It is highly extended
               • Interacting beta sheets can be arranged to form a parallel beta sheet
     • Tertiary
       • Three-dimensional conformation of a polipeptyde
         • Domain
           • It is a section of the protein structure sufficient to perform a particular chemical or physical task
     • Quaternary
       • Polypeptide composition of a protein and the spatial relationship with its promoter or subunit

4. Sources

   • Lysine
     • Meat, eggs, soy
   • Histidine
     • Meat, fish, nuts
   • Threonine
     • Cottage, wheat germ
   • Methione
     • Eggs, grains, nuts
   • Valine
     • Soy, cheese, whole grains
   • Isoleucine
     • Meat, fish, eggs
   • Leucine
     • Beans, soy, legumes
   • Phenylalanine
     • Meat, fish, beans
   • Tryptophan
     • Cheese, chicken, turkey