ABSTRACT
All students of biology and many others have heard of the central dogma of molecular biology (see Figure 1.3). DNA is transcribed into RNA, which then is translated into proteins. This central dogma is memorized by countless people every year and becomes ingrained in their thoughts about all molecular biology processes. While it is a useful hook for people to remember, it is an oversimplification of what actually goes on in cells (which is what Francis Crick indicated not long after he coined the term in 1956) and leads to misconceptions. First of all, as most are aware, there are several different categories of RNA. There are messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), and a diverse set of other small noncoding RNAs (ncRNAs) that function in the control of expression of the other RNAs. Where do these fit into this scheme? Figure 4.1 shows an overview of this more complex process.
