Final answer:
DNA replication in eukaryotes differs from prokaryotes, with eukaryotes having multiple origins of replication on linear chromosomes, whereas prokaryotes have a single origin on a circular chromosome. Eukaryotic replication is slower due to complex packaging around histones, and eukaryotic chromosomes feature unique telomere ends maintained by telomerase.
Step-by-step explanation:
DNA replication in eukaryotes and prokaryotes shares some fundamental steps but also reveals significant differences. One of the key distinctions lies in the origins of replication and the molecular machinery involved. In prokaryotes, which typically have a single, circular chromosome, replication begins at a single origin and progresses bi-directionally around the chromosome. However, eukaryotic chromosomes are linear and possess multiple origins of replication, allowing for the replication process to occur simultaneously at several locations within the genome.
The rate of replication in prokaryotes is much higher, with approximately 1000 nucleotides added per second, compared to about 100 nucleotides per second in eukaryotes. This difference is largely due to the more complex packaging of eukaryotic DNA, which is tightly coiled around histone proteins to form nucleosomes and requires additional steps during replication for unwinding and subsequent reassembly.
Eukaryotic replication machinery includes DNA polymerases such as pol δ6 for the leading strand and pol δ8 for the lagging strand, with DNA ligase sealing the gaps left after RNA primer removal. In contrast, prokaryotic replication heavily relies on DNA polymerase III for the addition of new nucleotides and other specialized polymerases for tasks like repair and primer removal.
At the ends of eukaryotic chromosomes are specialized structures called telomeres, which are maintained by the enzyme telomerase. Telomeres protect the linear chromosomes during replication from losing vital DNA sequences, which is a challenge that circular prokaryotic chromosomes do not face.