Amino Acids Structure and Properties

Amino Acids and Peptides

• Ornithine is a biologically important amino acid that does not enter the protein structure.
• Polypeptides contain more than 10 amino acids.
• The isoelectric point (pI) of an amino acid is the pH at which the amino acid has no net charge.
• Enkephalin is an example of a biologically active peptide.
• Glycine is the only optically inactive amino acid.
• The amino group (-NH2) and the carboxyl group (-COOH) are directly attached to the α carbon in each amino acid.
• Amino acids can be classified into three categories based on the number of carboxylic and amino groups: monoamino monocarboxylic acids, monoamino dicarboxylic acids, and diamino monocarboxylic acids.
• Aromatic amino acids contain rings in their side chains.
• Amino acids can be classified into two categories based on their nutritional needs: essential amino acids and non-essential amino acids.
• Methionine is a neutral amino acid that contains a sulfur atom in its side chain.
• Arginine and histidine are amino acids that must be taken with diet in growing infants and children.
• Peptides contain less than 50 amino acids linked by peptide bonds.
• Pantothenic acid is a part of coenzyme A.
• Beta-endorphin is a biologically active peptide with analgesic effect more powerful than morphine.
• Amino acids can be classified into acidic, basic, and neutral amino acids based on the pH of their side chains.
• Aromatic amino acids contain rings in their side chains.
• Aspartic acid and glutamic acid are classified as acidic and contain two carboxylic groups.
• All amino acids are optically active, except for glycine.
• Amino acids can be classified into two categories based on their nutritional needs: essential amino acids and non-essential amino acids.
• The amino group (-NH2) and the carboxyl group (-COOH) are directly attached to the α carbon in each amino acid.

Test your knowledge of the structure and properties of amino acids. This quiz covers the basic characteristics of amino acids, including the arrangement of functional groups and their optical activity.