Basic Amino Acids Three of the common amino acids have side chains with net positive charges at neutral pH: histidine, arginine, and lysine. The ionized group of histidine is …
Acidic Amino Acids There are two acidic amino acids – aspartic acid and glutamic acid – whose R groups contain a carboxyl group. Aspartic acid and glutamic acid thus …
Polar, Uncharged Amino Acids The polar, uncharged amino acids except for glycine contain R groups that can form hydrogen bonds with water. Thus, these amino acids are usually more …
Protein – Classification The structures and abbreviations for the 20 amino acids commonly found in proteins are shown in Figure 4.5. All the amino acids except proline have both …
Amino Acids can join via Peptide Bonds The crucial feature of amino acids that allows them to polymerize to form peptides and proteins is the existence of their two …
Structure of a Typical Amino Acid Amino acids in solution at neutral pH exist predominantly as dipolar ions (also called zwitterions). Amino acids can exist as zwitterions – substances …
Amino Acids are Chiral Molecules An a-amino acid consists of a central carbon atom, called the a carbon, linked to an amino group, a carboxylic acid group, a hydrogen …
Amino Acids Proteins are the essential agents of biological function, and amino acids are the building blocks of proteins. The diversity of the thousands of proteins found in nature …
