Question

Metabolism is a defining feature of all living organisms without exception. Isolated metabolic reactions in vitro are not living things but surely living reactions. Comment.

Answer 1

All living organisms are made of chemicals.

• There are thousands of metabolic reactions occurring simultaneously inside all living organisms, be they unicellular or multicellular. The sum total of all the chemical reactions occurring in our body is metabolism. All plants, animals, fungi and microbes exhibit metabolism.
• No non-living objects exhibit metabolism. Metabolic reactions can be demonstrated outside the body in a cell-free system. An isolated metabolic reaction(s) outside the body of an organism, performed in a test tube is neither living nor non-living. 

Hence, while metabolism is a defining feature of all living organisms without exception, isolated metabolic reactions in vitro are not living things but surely living reactions.