Overview Overview found in high concentrations in metabolically active cells Cell biology double membrane structure outer membrane high permeability due to high concentration of porins inner membrane impermeable to ions and molecules folded into cristae to ↑ surface area contains enzymes for electron transport chain (ETC) inner matrix contains circular DNA (mtDNA) maternal inheritance as mitochondria in the zygote come from the egg non-Mendelian inheritance synthesized in continous polycistronic manner including 13 coding genes 2 ribosomal RNA modules 22 transfer RNA segments examples of mtDNA disorders Leber's optic neuropathy degeneration of retinal ganglion cells progressive loss of central vision eventual blindness Pearson marrow-pancreas syndrome some protein synthesis occurs here most proteins are synthesized in cytoplasm and translocated to mitochondria Function oxidizes substrates NADH/FADH2 → NAH+/FAD generates ATP converts NADH/FADH2 into ATP via ETC stores Mg2+ and Ca2+ Mitochondrial Inheritance Pedigree Affected males transmit to none of their children Affected females transmit to all of their children