What is the Difference Between Primer and Promoter?

The main difference between primers and promoters lies in their functions and locations within DNA:

Primers:

• Primers are commercially synthesized short DNA sequences used to amplify target DNA sequences in a process called the Polymerase Chain Reaction (PCR).
• They have nucleotide sequences that are complementary to the flanking ends of the DNA double-strand, allowing them to serve as starting sequences for the synthesis of a new strand.
• Primers have about 20 base pairs and there are two types: forward primers and reverse primers.

Promoters:

• Promoters are specific regulatory DNA sequences found upstream of the transcription initiation site.
• They regulate gene transcription by providing binding sites for RNA polymerase and other transcription factors, defining the direction of transcription and indicating the sense strand of a gene.
• Promoters can have about 100-1000 base pairs and are classified into three types: core promoters, proximal promoters, and distal promoters.

In summary, primers serve as starting sequences for the synthesis of a new DNA strand in PCR, while promoters regulate gene transcription by providing binding sites for RNA polymerase and other transcription factors.

Comparative Table: Primer vs Promoter

Here is a table highlighting the differences between primers and promoters:

Please note that the information in the table above pertains to biological primers and promoters, as these are the most relevant and widely studied in the context of molecular biology.