Here's why:

* RNA polymerase's role: RNA polymerase is responsible for transcription, the process of copying genetic information from DNA into RNA.

* Translation's role: Translation is the process of using the information in messenger RNA (mRNA) to build a protein.

Think of it like this:

* Transcription (RNA polymerase): You're writing down the recipe (DNA) onto a notecard (mRNA).

* Translation: You're using the notecard to actually make the dish (protein) from the ingredients.

Therefore, RNA polymerase plays a crucial role in the first step of protein synthesis, while translation occurs in the second step.