Up until now we've mainly focused on RNA as a strand of nucleotides that contains the information encoded by DNA. RNA is so much more.

It turns out that there are many different types of RNA. In eukaryotes, these RNAs are grouped by which RNA polymerase transcribes them.

• RNA polymerase I family members transcribe ribosomal RNAs (rRNAs). rRNA helps the ribosome function properly as a protein-making machine. 
• RNA polymerase II family members transcribe the messenger RNAs (mRNAs) and some structural RNAs. mRNAs are the type of RNA that encode for proteins.
• RNA polymerase III family members transcribe transfer RNAs (tRNAs). There are also a wide variety of small RNAs that have numerous regulatory roles in the cell. We'll talk about the roles and functions of all these RNAs in more detail later.

What's Translation All About, Anyway?

When it comes to translation, it is all about cracking the code. And the key to this code cracking is the central dogma, of course. Have you forgotten it already?

No worries. Here's a little refresher. The central dogma is:

DNA → RNA → Protein.

The cell needs to take the information in the RNA and translate it into a totally new language: the protein language. Serious stuff.

Don't worry, though. We'll have you speaking protein language in no time.