noun, plural: substrates
A substratum or an underlying stratum.
The substance acted upon by an enzyme.
The earthy material in which an organism lives, or the surface or medium on which an organism grows or is attached.
The material (e.g. dirt, rocks, sand, gravel) in the bottom of a marine habitat, or one that forms the bed of a stream (or of an aquarium); the source of food for some microorganisms.
Word origin: L. Stratum = layer.
Related terms: substrate inhibition, substrate-level phosphorylation, substrate specificity, suicide substrate, enzyme-substrate complex.