The mitochondrial ATP synthase is composed of multiple proteins, and some of these proteins are encoded by genes in the nucleus. One of these proteins is called S . A mutation in the S gene deletes 21 base pairs that are immediately 3' to the start codon. The mutant S gene is transcribed and translated but the S protein remains in the cytoplasm. This mutant yeast cell can only grow anearobically, whereas wild type yeast can grow anaerobically or aerobically. Yeast grows as a haploid cell. In wild type cells in the presence of O2, the pH of the mitochondrial matrix is 8, but in cells with this mutant S gene, the pH is 7. Explain these results.
