Now, what that basically means is the cell must be able to control the process of transcription. It must be able to turn on transcripts prescription when we need to synthesize proteins and turn all transcriptions when we do not need to use those proteins. And this process is known as gene expression and gene regulation. Now, prokaryotic cells such as bacterial cells can regulate gene expression by using special types of molecules. Special types of proteins known as DNA binding proteins and DNA binding proteins used by prokaryotes come in two categories. We have repressors and we have activators.