From Molecules to Metabolism — VI. When Chemistry Began to Feed Back on Itself

A chemical system can regulate what enters and leaves.

But regulation becomes something more when its consequences return to the processes that produced them.

Suppose a reaction produces something that changes the conditions for that same reaction — directly or through other reactions.

Now the system is no longer simply moving through a sequence of events.

What happens becomes a condition for what happens next.

This is feedback.

A product can inhibit a pathway.

A change in concentration can accelerate another reaction.

A shift in one part of the network can alter the conditions elsewhere, which then feeds back into the original process.

The chemistry begins to respond to its own consequences.

This matters because persistence is no longer merely a matter of having a boundary or a cycle. The system can begin to compensate for changes that would otherwise disrupt its organisation.

Too much of something can reduce the process producing it.

Too little can increase it.

The system need not “know” what it is doing.

There need be no central controller.

The organisation itself can produce the correction.

This gives us another step in the emerging sequence:

reaction → consequence → altered condition → altered reaction.

Chemistry has begun to acquire a past that matters immediately to its future.

And once consequences can feed back into the processes that produced them, the system is no longer merely maintaining a pattern.

It is beginning to maintain the conditions of its own activity.

Metabolism is becoming more than chemistry that happens.

It is chemistry that, through its organisation, begins to keep happening.