When bacteriophages infect a bacterial cell , their normal mode of reproduction is to harness the replicational , transcriptional , and translation machinery of the host bacterial cell to make numerous complete viral particles , including the viral DNA or RNA and the protein coat . When bacteriophages ( viruses that infect bacteria ) infect a bacterial cell , their normal mode of reproduction is to harness the replicational , transcriptional , and translation machinery of the host bacterial cell to make numerous virions , or complete viral particles , including the viral DNA or RNA and the protein coat .