Amino Acids

Building blocks of proteins

Approximately 20 amino acids occur naturally. Humans can synthesise only ten of them. The remaining amino acids must be obtained from food (essential amino acids).

Amino acids can bind to one another in chains in a virtually infinite number of combinations to form large protein molecules. Chains of amino acids fold upon themselves to form a characteristic three-dimensional structure.

The function of a protein in an organism is defined by the sequence of amino acids. There is no one-to-one correlation between gene and protein "blueprint". Instead blueprints for specific proteins are created by the combining of individual gene segments. This explains why there are more proteins than genes.

The blueprint for every amino acid is encoded by three "letters" (bases) of DNA. Each of the 20 amino acids has its corresponding codeword (or "codon") comprising three base pairs.

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