. "\"The gel-like material, with considerable fine structure, that lies in the matrix space, or lumen, of a mitochondrion. It contains the enzymes of the tricarboxylic acid cycle and, in some organisms, the enzymes concerned with fatty acid oxidation.\" [GOC:as, ISBN:0198506732]" . . "mitochondrial matrix" . "mitochondrial lumen" . "NIF_Subcellular:sao-1899375636" . "NIF_Subcellular:sao1804523077" . "Wikipedia:Mitochondrial_matrix" . . . "mitochondrial stroma" .