DNA Replication

DNA must be replicated exactly before it can be divided so that there is is something to be passed down to its offspring. The process is as followed:
1. The DNA helical begin unwinding from the nucleosomes.
2. A helicase enzyme untwists the double helix and gradually separates the DNA molecule into two complementary nucleotide chains, exposing the nitrogen bases. The replication site is called the replication bubble. The Y-shaped region at each end of the replication bubble is called the replication fork.
3. Each nucleotide strand serves as a template, set of instructions, for building a new complementary nucleotide strand from free DNA precursors.
4. Enzymes are present in large complexes called replisomes. Primase enzymes send initiation of RNA primers t start DNA synthesis. They are replaced by DNA nucleotides eventually.
5. DNA polymerase III positions complementary nucleotides along the template strand and then covalent,t links them together. The leading strand is synthesized followed by the lagging stand. The lagging strand is constructed in segments in the opposite direction and requires a primer to initiate replication of each segment.
6. The short sections of DNA are put together by DNA ligase. Two DNA molecules are formed from the original helix that are identical to it. Each new molecule consists of one old and one new. This is called semi conservative replication. It also creates two new telomeres, or end pieces.
7. Histones, synthesized in the cytoplasm and imported to the nucleus, connect with the DNA and create two new chromatin strands. They unite and form chromatids. They remain attached by centromere and cohesin. When the cell enters anaphase of mitotic cell division, they are distributed to daughter cells, ensuring each had identical genetic information.