Flour - providing mainly carbohydrate and a little protein and mineral content.
Water - to bind the flour into a dough and act as a medium for the chemical reactions.
Yeast - to convert the carbohydrate in the dough to gas (carbon dioxide) causing the dough to rise.
Oil - to help the bread stay moist longer and extend its shelf life.
Salt - to add taste and extend shelf life.
Sugar - to provide nutrients for the yeast, making it work quicker.