Final answer:
In DNA synthesis, dCTP and other nucleotide triphosphates are added to the free 3'-OH end of the growing DNA strand by DNA polymerase. The DNA polymerase complex binds at the 3' end of the primer to extend the DNA chain in a 5' to 3' direction, using the 3' to 5' template strand.
Step-by-step explanation:
In DNA synthesis, the 3'-OH end of the primer is essential for the initiation of the replication process. DNA polymerases require a free 3'-OH group where they can add nucleotides to a growing DNA strand. The nucleotide triphosphate, such as dCTP, provides the 3'-OH group in the form of deoxycytidine that is incorporated into DNA. Initially, an RNA primer provides the 3'-OH necessary for DNA polymerase to begin DNA synthesis, and DNA polymerase extends the DNA from this point forward.
DNA polymerase adds nucleotides to the 3' end of the growing DNA fragment. This means that dCTP, as part of the DNA polymerase complex, would also bind at the 3' end to continue the chain elongation.
To proceed with DNA synthesis, DNA polymerases travel from 3' to 5' direction on the DNA template strand, synthesizing the new complementary strand in the 5' to 3' direction. This elongation process is facilitated by the primer which provides the essential 3'-OH group, allowing the DNA polymerase to add nucleotides, whereas RNA primase synthesizes the initial RNA primer.