Abstract
Terpenes belong to the largest class of secondary metabolites consisting of
five carbon isoprene units which are assembled through innumerable patterns
generating diverse structural motifs. Terpenes are linear or cyclic hydrocarbons,
whereas terpenoids are oxygen-containing terpene analogues found in all living
organisms. Steroids are a subclass of terpenoids that are biosynthesized from terpene
precursors. Terpenes, terpenoids and steroids are all derived from five-carbon isoprene
units assembled and arranged in different ways generating thousands of structurally
varied molecules. Terpenes and terpenoids are widely explored as biomaterials and
biofuels while steroids are used as drugs to increase protein synthesis in animals
besides their anti-inflammatory, anticancer and other properties. In this chapter, we
discuss the properties, functions and biosynthesis of terpenes and terpenoids in general
and steroids in particular to better understand their functions and prospective
applications.