A synthesis in which molecules with a specific chirality are predominantly synthesized, starting from reactants that do not have a specific chirality. A strong impetus for the development of asymmetric synthesis has come from the pharmaceutical industry, as target biological molecules in humans are themselves chiral. It is also hoped that asymmetric synthesis may give insights into why biologically important molecules such as amino acids and DNA have specific chiralities. Asymmetric synthesis frequently makes use of catalysts, with this process being called asymmetric catalysis.