What enzyme is responsible for binding together disconnected strands of DNA?

The enzyme responsible for binding together disconnected strands of DNA is DNA ligase. This enzyme plays a crucial role in DNA replication and repair processes by catalyzing the formation of phosphodiester bonds between nucleotides. When the DNA strands are broken or fragmented, DNA ligase is essential for sealing these gaps, thereby stabilizing the DNA structure and ensuring the integrity of the genetic material.

In addition, DNA ligase is particularly important during the processes of DNA replication, where Okazaki fragments are generated on the lagging strand, and during the repair of single-strand breaks. This capability to connect DNA strands helps maintain the continuity of the genetic code, which is vital for proper cellular function and organismal development.

While other enzymes mentioned have their specific functions—such as RNA polymerase, which synthesizes RNA from a DNA template, restriction enzymes, which cut DNA at specific sequences, and helicase, which unwinds the DNA helix during replication—they do not fill the role of connecting and mending DNA strands like DNA ligase does.