Final answer:
Eukaryotic DNA Replication is a complex process during the S phase of the cell cycle, involving multiple origins of replication and diverse enzymes such as helicase, DNA polymerases, and DNA ligase. It proceeds at a slower rate than prokaryotic replication and includes additional factors due to the complexity of eukaryotic chromosomes.
Step-by-step explanation:
Eukaryotic DNA Replication is the biological process of copying a eukaryotic organism's DNA. This complex task occurs during the synthesis (S) phase of the cell cycle and can be broken down into three main stages: initiation, elongation, and termination. Unlike prokaryotic organisms that have a single circular chromosome, eukaryotic genomes consist of multiple linear chromosomes which are much more intricate, leading to differences in the replication process.
During initiation, multiple origins of replication are activated on each chromosome. In humans, for example, there can be up to 100,000 origins of replication, with replication proceeding at approximately 100 nucleotides per second. These numerous replication origins are a solution to the relatively slow replication rate in eukaryotes compared to prokaryotes. Enzymes such as helicase and topoisomerase, and proteins including histones and the pre-replication complex, play crucial roles in initiating DNA replication.
The elongation stage involves the continuous synthesis of the leading strand by polymerase enzyme pol δ and the discontinuous synthesis of the lagging strand by pol ε. A sliding clamp protein ensures DNA polymerases remain attached to the DNA strand. Additionally, RNase H, not found in prokaryotes, removes RNA primers which are then replaced with DNA nucleotides by other enzymes before DNA ligase seals the gaps.
In termination, the replication machinery disassembles after the entire chromosome has been replicated, ensuring each new cell has a complete set of chromosomes after cell division. Eukaryotic DNA replication, being more complex than prokaryotic replication, incorporates additional proteins and enzymes to manage the intricate architecture and vast amount of genetic information present in eukaryotic cells.