Proteins: Fundamental Chemical Properties


Proteins are the most abundant class of biological macromolecules as they represent over 50% of the dry weight of cells. They are involved in virtually all chemical reactions and processes occurring in life forms as well as in the mechanical support and filamentous architecture within and between cells. Irrespective of their functional or structural role, they all are formed from the same 20 building blocks, called amino acids, which are joined end‐to‐end through covalent linkages termed peptide bonds.

The size, ionisation properties and hydrophobicity/hydrophilicity of the constituent amino acids influence the solubility, stability and structural organisation of proteins that exist essentially in either aqueous or membrane environments.

The amino acid sequences (primary structures) determine the higher structural levels (secondary and tertiary) of proteins and specify their biological properties.

Key Concepts:

  • Proteins occupy a prominent position in all biological systems, both quantitatively and qualitatively.

  • Irrespective of their structural or functional role, all proteins are built from the same fundamental blocks, the amino acids.

  • The physico‐chemical properties of the constituent amino acids determine the structure and biological function of proteins.

Keywords: amino acid; chemical properties of proteins; protein structure

Figure 1.

Major periodic elements of protein secondary structure.


Further Reading

Kannicht C (2008) Post‐translational Modifications of Proteins – Tools for Functional Proteomics, 2nd edn. New York: Humana Press.

Kukol A (2008) Molecular Modeling of Proteins. New York: Humana Press.

Rehm H (2006) Protein Biochemistry and Proteomics. London: Academic Press.

Shriver JW (2009) Protein Structure, Stability, and Interactions. Berlin: Springer.

Whitford D (2005) Proteins: Structure and Function. Oxford: Wiley.

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Cozzone, Alain J(Apr 2010) Proteins: Fundamental Chemical Properties. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0001330.pub2]