DNA polymerase III synthesizes new DNA in which direction?

DNA polymerase III synthesizes new DNA in the 5' to 3' direction, which is the fundamental feature of DNA polymerases. This means that during DNA replication, the enzyme adds new nucleotides to the growing strand by attaching them to the 3' end of the existing DNA strand. Each nucleotide that is added has a phosphate group that connects to the hydroxyl (OH) group of the existing chain, thus elongating the DNA strand.

This directionality is critical because it reflects the chemical nature of nucleic acid synthesis. The nucleotides are always added to the 3' end, ensuring that the new strand is built in a specific orientation. Additionally, DNA synthesis must always proceed in this 5' to 3' direction, aligning with the antiparallel nature of the double helix structure of DNA. Understanding this concept is crucial for many processes in molecular biology, including DNA replication and repair.