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Are individual molecules and atoms living?

Q: Are the molecules living things? Because molecule forms proteins, which forms cells and cells are living?

Krishna: To answer this question, first we will have to define what a 'living' organism is.

There is currently no consensus regarding the definition of life. One popular definition is that organisms are open systems that maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment, respond to stimuli, reproduce and evolve (2).

If we take all these parameters into account, molecules cannot be considered as living. The individual molecules cannot do all these things mentioned above.

Then how can you consider them as living?

Cells are living. But only when inside a living body. Aren't cells inside a dead body non-living?

Even single cell-celled entities like bacteria can be killed. Then the molecules and proteins that constitute a living entity become non-living.

Individual Molecules outside a living entity are non-living.

Properties of matter decide interactions too. Therefore, there might be something about the properties of matter, as currently measured, that contains some “essence” of living entities. Not all molecules are replicant like DNA or proteins but explicit to a small set of the phenomenological groupings that arise from it. There is waste too! Molecules are present in non-living matter too like sand, water, oil, and gas, wastes like feces and urine. It is the way and place matter is arranged that matters.

The property arises from the way and place of the grouping, not the components. A unified theory of physics will arrive at a point where matter has no properties except relative location on which an action principle works. So, life would arise from phenomenological groupings, not from properties of matter.

Life requires several steps up in order and complexity. That can be obtained only by way of interactions of specific groupings of molecules working in a specific way.

There are molecules in the waste inside your body, in the digestive system and urinary system. Are these molecules living ? NO!

Although individual oxygen, carbon, nitrogen and iron atoms can become part of blood, contribute in some way with their properties, they themselves cannot be life.

A heme is an organic, ring-shaped molecule and is made from 4 pyrroles, which are small pentagon-shaped molecules made from 4 carbons and 1 nitrogen. Due to its special structure, a heme is capable of holding, or “hosting” an iron atom. If the tetrapyrrole has substitutions on the side chains which allow it to hold a metal ion, it is called a porphyrin. Thus, a heme is an iron-holding porphyrin.The iron atoms in a heme are held in place by the balanced attractive forces of the four nitrogen atoms.

Hemes are used for two known reasons: to carry oxygen and to transport or store electrons. Living organisms use the heme molecule, in complex with specially-shaped proteins, to transport oxygen and move electrons. These special proteins, like hemoglobin and myoglobin, are made to help the heme complex hold or release oxygen at the appropriate times (3).

Heme molecule: Source: Wikipedia

Blood taken as a whole is a living tissue, even though technically the cells (red cells, white cells and platelets) are the only part which is alive.

Red blood cells when taken outside a living body can remain alive in a fridge for a month if they are kept in the right suspension. White cells deteriorate after only a couple of days. Platelets remain alive for about 7 days. The non-cellular parts of blood deteriorate very quickly too: donated blood is separated into different components for storage. Blood is hardly ever kept all together (whole).

During the storage the blood cells don’t do anything except remain alive. If they are transfused into another person they start doing their job again.

After some time all the blood cells deteriorate and die.

How long can we keep normal human cells alive outside the body? By providing assistance only for a few days (1).

Afterwards they die and cannot perform processes that can be defined as life.

Therefore, the answer to your question is - individual atoms and molecules are not living. They become a part of life only when arranged in certain ways and places in living organisms and assist in the 'life's processes'.

Footnotes:

1. https://sciencecommunication.quora.com/How-long-can-we-keep-human-c...

2. https://kkartlab.in/group/some-science/forum/topics/qs-people-asked...

3. https://biologydictionary.net/heme/

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