08 June 2025, 15:01 (IST)

I’ve been thinking a lot about ambiguity and was interested to find the term “substrate ambiguity” in the context of biological systems.

A substrate is the surface with which an enzyme interacts. Enzymes typically interact with a specific substrate.

The “lock and key” model of enzyme-substrate interactions proposes that the active site of an enzyme conforms to the shape of the substrate perfectly.

Substrate ambiguity (or promiscuity) refers to the ability of an enzyme to interact with multiple substrates.

In the abstract, ambiguity is essentially a one-to-many relationship, for example:

The potential interaction between an ambiguous substrate and multiple enzymes.

The interpretative mapping between a polysemous phrase and multiple meanings.

The user pathways from a software interface and multiple functionalities.

Ambiguity is usually considered a flaw:

It can mean a design is underspecified.

It can cause misunderstandings.

It can be genuinely dangerous.

Sometimes, ambiguity can be useful:

In art, it can be interesting.

In science, it provokes hypotheses.

In games, it prompts discovery.

Ambiguity in biological systems also applies to chaperones, molecules that assist the folding of proteins.

Chaperones that can assist many proteins in this way are “ambiguous chaperones”.

More commonly, they are referred to as “promiscuous chaperones”, which is my personal candidate for the funniest scientific term.