ABSTRACT
This chapter will discuss the DNA within a bacterial cell that makes up the genome, including the contribution to the genome of genes that are essential to life. Genetic features within the bacterial genome, such as the rRNAs and tRNAs that are noncoding yet essential to life processes will also be discussed. This chapter will explore the concept of the genome in bacteria, where there is generally one circular chromosome that contains the whole genome, and how this is not true of all bacterial species. Some bacteria have multiple chromosomes that together make up the whole genome. Some bacteria have linear chromosomes as their genome or linear chromosomes that together with circular chromosomes make up the genome. Extra-chromosomal DNA can also be present within the bacterial cell, generally present as plasmids, which can contribute additional traits to the bacteria. The structure and composition of bacterial genomes will be explored in this chapter, including how these structures can contribute to the expression of genes and the consequences of transcription, translation, and replication happening simultaneously within the bacteria cell. Changes in the genome are also discussed, including how these can arise and therefore drive evolution of bacteria.
