Multiple Choice
In the context of DNA replication, what is the primary function of DNA ligase?
36
views
8. DNA Replication
Overview of DNA Replication
Multiple Choice
In the overview of DNA replication, what is the primary function of DNA ligase?
A
It seals nicks in the sugar-phosphate backbone by forming phosphodiester bonds, joining Okazaki fragments on the lagging strand.
B
It adds nucleotides to the growing DNA strand in the to direction using the template strand.
C
It synthesizes RNA primers to provide a 3' - O H group for DNA polymerase to extend.
D
It unwinds the parental DNA double helix ahead of the replication fork by breaking hydrogen bonds.
Verified step by step guidance1
Understand the context of DNA replication, where the DNA double helix is copied to produce two identical DNA molecules.
Recognize that during replication, the leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.
Identify that these Okazaki fragments are initially separate pieces of DNA with gaps or 'nicks' between them in the sugar-phosphate backbone.
Know that DNA ligase is the enzyme responsible for sealing these nicks by forming phosphodiester bonds, thus joining the Okazaki fragments into a continuous strand.
Distinguish the role of DNA ligase from other enzymes: DNA polymerase adds nucleotides, primase synthesizes RNA primers, and helicase unwinds the DNA helix.
Related Videos
Related Practice
