Biology Terminology Lecture 10 Notes | Lindsey Wilson College

University:
Lindsey Wilson College
Course:
BIOL 1103 | Principles of Biology
Academic year:

2022
Views:

15

Pages:

1
Author:

Richard Mitchell

Lecture 10 origins of replication Replication begins at this special sites where the two DNA strands are separated, opening up a replication “bubble” replication fork, At the end of each replication bubble is a replication fork, a Y-shaped region where new DNA strands are elongating Helicases are enzymes that untwist/unwind the double helix at the replication forks Single-strand binding protein binds to and stabilizes singlestranded DNA until it can be used as a template Topoisomerases correct “overwinding” ahead of replication forks by breaking, swiveling, and rejoining DNA strands DNA polymerases Enzymes catalyze the elongation of new DNA at a replication fork the lagging strand To elongate the other new strand, called, DNA polymerase must work in the direction away from the replication fork Okazaki fragments The lagging strand is synthesized as a series of segments called which are joined together by DNA ligase mismatch repair of DNA, repair enzymes correct errors in base pairing nucleotide excision repair A nuclease cuts out and replaces damaged stretches of DNA telomeres Eukaryotic chromosomal DNA molecules have at their ends nucleotide sequences telomerase an enzyme catalyzes the lengthening of telomeres.