Amino Acids - Structure, full name, & acidity
ALA
ALA - Alanine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 Tend to cluster together on the inside of proteins, stabilizing protein structure via hydrophobic interactions.
ARG
ARG - Arginine Positively charged R groups - Basic pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 **pK3 (=NH2+): 6.00
ASN
ASN - Asparagine Polar, uncharged R groups: H bonds with water pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3
ASP
ASP - Aspartate Negatively charged R groups - Acidic pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 **pK3 (-COOH): 3.65 ** Second carboxyl group with a net negative charge at pH 7.0.
CYS
CYS - Cysteine Polar, uncharged R groups: H bonds with water pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 ** pK3 (-SH): 8.18 **Pairs of cysteines can oxidize through a disulfide bonds to form cystine, which is non-polar and strongly hydrophobic.
GLN
GLN - Glutamine Polar, uncharged R groups: H bonds with water pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3
GLU
GLU - Glutamate Negatively charged R groups - Acidic pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 **pK3 (-COOH): 4.25 ** Second carboxyl group with a net negative charge at pH 7.0.
GLY
GLY - Glycine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60
HIS
HIS - Histidine Positively charged R groups - Basic pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 **pK3 (-NH): 12.48 **His is the only amino acid with an ionizable side chain that has a pKa near neutrality. Therefore, His can serve as a proton donor or acceptor in many enzyme-catalyzed reactions Phosphorylation by ATP for reversible covalent modification enzyme regulation
ILE
ILE - Isoleucine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 ***ESSENTIAL ***Chiral side chain Tend to cluster together on the inside of proteins, stabilizing protein structure via hydrophobic interactions.
LEU
LEU - Leucine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 Tend to cluster together on the inside of proteins, stabilizing protein structure via hydrophobic interactions. ***ESSENTIAL
LYS
LYS - Lysine Positively charged R groups - Basic pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 **pK3 (-NH3+): 10.53 ***HIGHEST OCCURRENCE IN PROTEINS Acetylation by (acetyl-coA) or ubiquitination for reversible covalent modification enzyme regulation
MET
MET - Methionine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 ***ESSENTIAL
PHE
PHE - Phenylalanine Aromatic R groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 ***ESSENTIAL
PRO
PRO - Proline Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60
SER
SER - Serine Polar, uncharged R groups: H bonds with water pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 Phosphorylation by ATP for reversible covalent modification enzyme regulation
THR
THR - Threonine Polar, uncharged R groups: H bonds with water pK1(-COOH): ~2.1 and pK2(-NH3+): ~9.3 ***Chiral side chain Phosphorylation by ATP for reversible covalent modification enzyme regulation
TRP
TRP - Tryptophan Aromatic R groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 ***ESSENTIAL ***LOWEST OCCURRENCE IN PROTEINS
TYR
TYR - Tyrosine Aromatic R groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 **pKr(-OH): 10.07 The hydroxyl group can form hydrogen bonds and plays an important functional role in some enzymes Phosphorylation or Adenylation by ATP for reversible covalent modification enzyme regulation
Essential Amino Acids
The Whole Food Ladder Must Have Various Key Ingredients threonine, tryptophan, phenylalanine, leucine, methionine, histidine, valine, lysine, and isoleucine.
VAL
VAL - Valine Nonpolar, aliphatic R Groups: pK1(-COOH): ~2.34 and pK2(-NH3+): ~9.60 Tend to cluster together on the inside of proteins, stabilizing protein structure via hydrophobic interactions. ***ESSENTIAL
