The processes of DNA replication, gene transcription and protein translation are simpler in prokaryotes compared to eukaryotic cells. Ongoing scientific research is continually uncovering the complexities of these processes. Bacteria and other prokaryotes lack a nuclear envelope. Consequently, gene transcription and protein translation can take place simultaneously. All eukaryotic cells contain a membrane bound nucleus. By extension, transcription and translation are separated in space and time.
Lacking a nuclear membrane results in certain advantages for bacteria in comparison to eukaryotes. Gene expression is inherently faster, and bacteria can dispense with RNA processing. Messenger RNA can be translated into protein even as downstream regions of a particular gene are still being transcribed.
DNA replication in prokaryotes is also simpler than in eukaryotes. Prokaryotic genomes are far smaller than their eukaryotic counterparts. Also, bacterial chromosomes tend to be circular rather than linear. Starting at a single origin of replication, a bacterium like E. coli replicates its DNA in as little as 40 minutes. Eukaryotic cells contain large linear chromosomes, each with multiple origins of replication, a centromere to hold homologous pairs of chromosomes together and telomeres on each end. Replicating a structure this size takes hours, even for unicellular eukaryotes like yeast.