Final answer:
DNA polymerases are the enzymes that replicate DNA in the cell, using energy from DNA nucleoside triphosphates to add nucleotides to a new DNA strand.
Step-by-step explanation:
The molecules that function to replicate DNA in the cell are DNA polymerases. These enzymes are responsible for adding complementary nucleotides to the growing DNA chain during replication, using the template strand as a guide. DNA nucleoside triphosphates, like ATP, GTP, TTP, and CTP, supply both the nucleotides and the energy needed for the formation of the new DNA strand by releasing energy when their phosphate bonds break, which then helps form the phosphodiester bond between the incoming nucleotide and the growing DNA chain.
In prokaryotes, there are three main types of DNA polymerases: DNA pol I, DNA pol II, and DNA pol III, with DNA pol III being primarily responsible for DNA synthesis during replication. In eukaryotes, different polymerases such as DNA polymerase alpha, delta, and epsilon, along with accessory proteins, carry out the replication process. The entire set of enzymes and proteins involved in this process is called the DNA replicase system or replisome.