Mitochondrial matrix
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.
Mitochondrial inner matrix; Mitochondrial Matrix; Matrix granule
In the mitochondrion, the matrix is the space within the inner membrane. The word "matrix" stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm.