Diagram showing the proposed pathways for the metabolism of pyruvate in Pi-starved cells. Abbreviations: Q, ubiquinone; G6P, glucose 6-phosphate; cyt, cytochrome quinol oxidase; FAD, flavin adenine dinucleotide; PEP, phosphoenolpyruvate; PDHc, PDH complex; Pta, phosphotransacetylase; AckA, acetate kinase.