Explain the process of DNA replication.

Explanation

DNA replication starts at a point called origin (vri). A unit of replication with one origin, is called a replicon. During replication, the 2 strands unwind and separate by breaking H-bonds in presence of an enzyme, Helicase.
Unwinding of the DNA molecule at a point forms a .Y.-shaped structure called replication fork. The separated strands act as templates for the synthesis of new strands. DNA replicates in the 5.`to`3. direction.
Deoxyribonucleoside triphosphates (dATR dGTP, dCTP & TTP) act as substrate and also provide energy for polymerization. Firstly, a small RNA primer is synthesized in presence of an enzyme, primase. In the presence of an enzyme, DNA dependent DNA polymerase, many nudeotides join with one another to primer strand and form a polynucleotide chain (new strand). The DNA polymerase forms one new strand (leading strand) in a continuous stretch in the 5.` to` 3. direction. (Continuous synthesis).

The other new strand is formed in small stretches (Okazaki fragments) in 5 3. direction (Discontinuous synthesis).
The Okazaki fragments are then joined together to form a new strand by an enzyme, DMA ligase. This new strand is called lagging strand.