All industry is made up of four sectors that are a linked together like a chain: primary, secondary, tertiary and quaternary industry. Industries in the primary and secondary sectors are the ...

All industry is part of a chain that starts with primary ... and secondary industry: the processing of these raw materials into usable products. Next in the chain come tertiary and quaternary ...

The linear sequence of amino acids within a protein is considered the primary structure of the protein. Proteins are built from a set of only twenty amino acids, each of which has a unique side chain.