How Are RNA Primers Different from DNA in DNA Synthesis?

What is the key difference between RNA primers and DNA in the process of DNA synthesis?

A. The RNA primers have three phosphates on each nucleotide.

B. The RNA primers are not properly based paired so they can be removed.

C. The RNA primers are made up of RNA, not DNA.

D. The RNA primers do not have a 3'-OH.

Answer:

The key difference between DNA and the RNA primers used to initiate DNA synthesis lies in their composition. The correct answer is C. The RNA primers are made up of RNA, not DNA.

RNA primers are essential components in the process of DNA replication. These short sequences of RNA serve as the starting point for DNA polymerases to add nucleotides and initiate the synthesis of new DNA strands.

Unlike the DNA molecule itself, which is composed of deoxyribonucleotides, RNA primers are composed of ribonucleotides. This difference in composition allows RNA primers to provide the initial base for DNA polymerases to begin synthesizing new DNA strands.

Once the DNA synthesis process is underway, the RNA primers are eventually removed and replaced with DNA nucleotides, resulting in a fully synthesized DNA molecule. This process ensures that the new DNA strands are composed entirely of DNA nucleotides, despite the initial use of RNA primers to kickstart the synthesis process.

Overall, RNA primers play a crucial role in facilitating DNA replication by providing a temporary scaffold for DNA polymerases to build upon. Their unique composition of RNA sets them apart from the DNA molecule itself during the initial stages of DNA synthesis.