Mitochondrial respiration is an important topic in biochemical courses, but at the same time it is a very arduous and challenging subject for the students to comprehend. In teaching laboratories, experiments are also difficult to perform because mitochondrial isolation as well as oxygen consumption determinations require expensive equipment, rarely present in Mexican teaching laboratories. For this purpose, we adapted the 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenyltetrazolium bromide (MTT) assay, usually done with cell lines, to corroborate mitochondrial respiration in yeast. We used the reduction of the MTT to learn and distinguish the respiratory yield between different substrates as well as the effects of respiratory inhibitors. This is an economical, easily done laboratory experiment that quantifies mitochondrial functionality and provides a good idea of the respiratory process.