Regulation of Gene Expression: Operons, Epigenetics, and Transcription Factors

We learned about gene expression in biochemistry, which is comprised of transcription and translation, and referred to as the "central dogma" of molecular biology. But how is this process regulated? How does a cell know which genes to express and when? Well it's pretty complicated, but let's just get our feet wet by looking at operons, epigenetics, and transcription factors!