Mitochondria are enclosed by a double-membrane system made up of an inner and an outer membrane. The space between these two membranes is called (surprise!) the intermembrane space. The inner membrane encloses the interior of the mitochondrion, which is known as the mitochondrial matrix.The inner membrane also forms a large number of folds, called cristae, that extend into the matrix.See Fig.he space between these two membranes is called (surprise!) the intermembrane space. The inner membrane encloses the interior of the mitochondrion, which is known as the mitochondrial matrix. The inner membrane also forms a large number of folds, called cristae, that extend into the matrix. See Fig.
1. relative atomic mass - (chemistry) the mass of an atom of a chemical element expressed in atomic mass units. atomic mass, atomic weight. mass-the property of a body that causes it to have weight in a gravitational field.
Atomic and molecular weights are measured on a scale of atomic mass units (amu) , where 1 amu is defined as exactly one-twelfth of the mass of a I2 C atom. A quantity of a chemical substance (atoms, molecules, or ions) equal to the atomic weight expressed in grams is defined as 1 mole of that substance.