Here's why:

* DNA carries the genetic code. The genetic code is the set of instructions that determines the amino acid sequence of proteins. It is encoded in the sequence of nucleotides within DNA.

* Proteins are the product of the genetic code. DNA is transcribed into RNA, and RNA is translated into proteins. Proteins are built based on the information contained in the genetic code.

Think of it like this:

* DNA is like a recipe book. It contains all the instructions for making different proteins.

* RNA is like a copy of the recipe. It carries the instructions from the DNA to the protein-making machinery.

* Proteins are like the finished dish. They are built according to the instructions in the DNA recipe.

So, while proteins are essential for life and carry out many functions, they don't hold the genetic code. The code itself resides within DNA, and proteins are simply the products of that code.