Final answer:
DNA replication in E. coli takes about 42 minutes for its 4.6 million base pairs, indicating a highly efficient process that replicates 1000 nucleotides per second and sets it apart from slower eukaryotic replication.
Step-by-step explanation:
Time Required for DNA Replication in E. coli
The time required for DNA replication in the bacterium Escherichia coli (E. coli) is approximately 42 minutes to replicate its entire genome of 4.6 million base pairs. E. coli's DNA replication starts at a single origin of replication and proceeds bidirectionally. This efficient mechanism allows the bacterium to add about 1000 nucleotides per second. The rapidity of this process is crucial since bacterial cells can divide every hour, necessitating a swift duplication of DNA to ensure all cells inherit a complete set of genetic information. Remarkably, the replication occurs with few mistakes despite its speed, which is much more rapid compared to eukaryotic replication involving multiple origins.
Studying the DNA replication in E. coli has provided significant insights into the molecular biology of prokaryotic cells. The pioneering work by Meselson and Stahl using 15N helped in understanding the semiconservative nature of DNA replication. Prokaryotic replication is simpler and faster, which is partly why it has been studied exhaustively. In contrast, replication in eukaryotic organisms occurs at a slower rate due to the larger size of their genomes, multiple origins of replication, and a more complex replication machinery.