Metabolism:-

• It is the sum total of all biochemical reactions inside a living system.
• It is the defining feature of living organisms.
• Metabolic reactions can be demonstrated outside the body in cell-free systems.
• Isolated metabolic reactions in vitro are not living things but are living reactions.
• Metabolism is both anabolism and catabolism found in living organisms.
• Thus, metabolism is a perfect defining property of living organisms.