BIOLOGY 1A03 Lecture Notes - Lecture 20: Primase, Embryonic Stem Cell, Telomere

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Lovaye Kajiura

Document Summary

In reality although errors in dna replication are rare, they certainly can occur. This can occur during the initial pairing between incoming nucleotides and those of the template strand. However, the cell has an innate proofreading mechanism. During dna replication, dna polymerases are able to proofread each added nucleotide relative to the template strand, as each dna nucleotide is added to the growing daughter strand. If an incorrect nucleotide pairing is detected, dna polymerase removes the incorrect nucleotide, the correct nucleotide is added, and then replication can continue by the. While there is a high degree of accuracy with which dna polymerase exudes its proofreading capabilities, mismatched nucleotides can sometimes be evaded by this proofreading mechanism. Sometimes other enzymes can help with the correction of replication errors. As we have seen, replication in prokaryotes begins at one origin of replication, afterwhich replication continues around the circular chromosome from this one initiation site.