Amino Acid Properties

Amino Acid Properties

• Amino acids can be classified into three main categories: nonpolar, polar, and electrically charged.

Nonpolar Amino Acids

• Nonpolar amino acids are hydrophobic (water-repelling) and tend to be located in the interior of proteins.
• Examples of nonpolar amino acids include:
  • Glycine (Gly)
  • Alanine (Ala)
  • Valine (Val)
  • Leucine (Leu)
  • Isoleucine (Ile)
  • Methionine (Met)
  • Tryptophan (Trp)
  • Phenylalanine (Phe)
  • Proline (Pro)

Polar Amino Acids

• Polar amino acids are hydrophilic (water-attracting) and tend to be located on the surface of proteins.
• Examples of polar amino acids include:
  • Serine (Ser)
  • Threonine (Thr)
  • Cysteine (Cys)
  • Tyrosine (Tyr)
  • Asparagine (Asn)
  • Glutamine (Gln)

Electrically Charged Amino Acids

Acidic Amino Acids

• Acidic amino acids have a negative charge.
• Examples of acidic amino acids include:
  • Aspartic Acid (Asp)
  • Glutamic Acid (Glu)

Basic Amino Acids

• Basic amino acids have a positive charge.
• Examples of basic amino acids include:
  • Lysine (Lys)
  • Arginine (Arg)
  • Histidine (His)