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.
Density is the mass of a substance that would fill 1 cm3 at room temperature. Relative atomic mass. The mass of an atom relative to that of carbon-12. This is approximately the sum of the number of protons and neutrons in the nucleus. Where more than one isotope exists, the value given is the abundance weighted average. Isotopes. Atoms of the same element with different numbers of neutrons.