A single unit of a large carbon-based molecule is called a monomer.

Here's a breakdown:

* Monomer: A small molecule that can be joined to other similar molecules to form a larger molecule, called a polymer. Think of it as a building block.

* Polymer: A large molecule made up of repeating monomer units.

Examples of monomers and their polymers:

* Monomer: Glucose (a simple sugar)

* Polymer: Starch, Cellulose (both are complex carbohydrates)

* Monomer: Amino acid

* Polymer: Protein

* Monomer: Nucleotide

* Polymer: DNA, RNA

Let me know if you'd like more details on any of these examples!