The subunits of contain a base, a five-carbon sugar, and a phosphate group. The subunits of are amino acids. Some of the subunits of must come from food. DNA and RNA are.

I'm assuming this is fill-in-the-blank, so

The subunits of nucleic acids contain a base, a five-carbon sugar, and a phosphate group. The subunits of proteins are amino acids. Some of the subunits of proteins must come from food. DNA and RNA are nucleic acids.

These are standard definitions of the properties of nucleic acids versus proteins. These are known as the building blocks of the cell, so it's a good idea to familiarize yourself with the basics!