Final answer:
Primase is the enzyme that synthesizes short RNA primers for DNA replication. It provides a starting point for DNA polymerase to synthesize the new DNA strand. This process is crucial for both continuous synthesis on the leading strand and discontinuous synthesis on the lagging strand.
Step-by-step explanation:
The enzyme that synthesizes short stretches of RNA nucleotides to get DNA replication started is called primase.
Primase is an RNA polymerase enzyme that creates an RNA primer necessary for the initiation of DNA synthesis.
At the replication fork, primase synthesizes a short sequence of RNA nucleotides (about 5-10 bases long), which are complementary to the template DNA strand.
This RNA primer provides a free 3'-OH group that is essential for DNA polymerase to begin the addition of DNA nucleotides, thereby forming the new DNA strand.
DNA replication is a bidirectional process that requires a primer for both the leading and the lagging strands.
The leading strand is synthesized continuously, while the lagging strand is synthesized in shorter segments known as Okazaki fragments.
Each fragment must be started with a new RNA primer. After synthesis, these RNA primers are removed and replaced with DNA nucleotides, and the gaps are sealed by an enzyme called DNA ligase.