substrate

The material or substance on which an enzyme acts.

A surface on which an organism grows or is attached.

An underlying layer; a substratum.

An indigenous language that contributes features to the language of an invading people who impose their language on the indigenous population.

A substratum.

To strew or lay under anything.

A substratum.

Having very slight furrows.

To strew or lay under anything.

What an enzyme acts upon.