DNA replication proteins

single-strand binding protein

binds to and stabilizes single-stranded DNA until it can be used as a template

DNA ligase

joins 3' end of DNA that replaces primer to rest of leading strand and joins Okazaki fragments of lagging strand

DNA pol I

removes RNA nucleotides of primer from 5' end and replaces them with DNA nucleotides

primase

synthesizes an RNA primer at 5' end of leading strand and of each Okazaki fragment of lagging strand

helicase

unwinds parental double helix at replication forks

DNA pol III

using parental DNA as a template, synthesizes new DNA strand by covalently adding nucleotides to the 3' end of a pre-existing DNA strand or RNA primer

why do Okazaki fragments exist

Basically, because DNA Polymerase can only work in one direction (it needs an open 3' end to add nucleotides to), it can't just add nucleotides to the side that has an open 5' end. Instead, Primase adds multiple RNA primers and then DNA Polymerase works backwards, between the primers. These DNA nucleotides that are put in place between the primers are the Okazaki fragments

Okazaki fragments

Okazaki fragments are short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication. They are complementary to the lagging template strand, together forming short double-stranded DNA sections. Okazaki fragments are the small DNA pieces formed between RNA primers during discontinuous replication on the lagging strand