BIO130H1 Lecture Notes - Lecture 3: Centromere, Cooperative Binding, Semiconservative Replication

• School: UTSG
• Department: Biology
• Course: BIO130H1
• Professor: Melody Neumann

Document Summary

Base-pairing underlies dna replication and dna repair: dna templating is the mechanism the cell uses to copy the nucleotide sequence of one. Dna strand into a complementary dna sequence: dna polymerase was the first nucleotide-polymerizing enzyme discovered. For the lagging strand, the direction of nucleotide polymerization is opposite to the overall direction of dna chain growth. The synthesis of this strand by a discontinuous backstitching mechanism means that dna replication requires only the 5"-to-3" type of. Dna molecules with a mismatched nucleotide at the 3"-oh end of the primer strand are not effective as templates because the polymerase cannot extend such as strand. Dna polymerase molecules correct such a mismatched primer strand by means of a separate catalytic site. This requirement safeguards against errors: rna polymerase doesn"t have the same requirement, and as a result experiences an error rate 100, 000 times greater than dna polymerase. A special nucleotide-polymerizing enzyme synthesizes short rna primer molecules on the.