Final answer:
DNA polymerase III in E. coli adds nucleotides to the 3' end of a growing DNA strand, essential for DNA synthesis.
Step-by-step explanation:
In E. coli, the function of DNA polymerase III is to add nucleotides to the 3' end of a growing DNA strand during DNA replication. This enzyme synthesizes a new strand of DNA that is complementary to the template strand, by adding nucleotides in successive condensation reactions and it is essential for DNA synthesis during cell division. This smooth process occurs with the help of energy released from the hydrolysis of nucleoside triphosphates, much like ATP hydrolysis provides energy for various cellular activities.