ABSTRACT
This chapter explains how cells decode and use the information in their genomes. It deals with the first step in decoding a genome: the process of transcription by which an Ribonucleic acid (RNA) molecule is produced from the deoxyribonucleic acid (DNA) of a gene. Despite the universality of the central dogma, there are important variations in the way in which information flows from DNA to protein. Like proteins, many of these RNAs fold into precise three-dimensional structures that have structural, catalytic, and regulatory roles in the cell. The DNA in genomes does not direct protein synthesis itself, but instead uses RNA as an intermediary. Genome sequences reveal that the DNA strand used as the template for RNA synthesis varies from gene to gene depending on the location and orientation of the promoter. Transcription and translation are the means by which cells read out, or express, the genetic instructions in their genes.
