The living organisms are made up of molecules. These
are of various sizes, classes, functions, etc. They need to
change in some other biomolecules. These conversions
are chemical reactions or metabolic reactions.
Metabolism is a defining feature of life, as living things
depend on various biochemical reactions. These
reactions can be demonstrated outside the body in
cell-free systems, which are neither living nor
non-living. Isolated metabolic reactions in vitro are thus,
not living things, but surely living reactions.