4.15. BIOLOGICAL FUNCTIONS OF DNA

4.15.1. DNA REPLICATION

1. Cell division is essential for an organism to grow
2. During this DNA make copy → So, two daughter cells have the same genetic information as their parent.
3. Called DNA replication.
4. Here, the two strands are separated and then each strand's complementary DNA sequence is recreated by an enzyme called DNA polymerase.
5. This enzyme makes the complementary strand by finding the correct base through complementary base pairing, and bonding it onto the original strand.
6. As DNA polymerases → extend a DNA strand in a 5′ to 3′ direction → So, different mechanisms are used to copy the antiparallel strands of the double helix.
7. Thus, base on the old strand dictates which base appears on the new strand, and the cell ends up with a perfect copy of its DNA.

4.15.2. TRANSCRIPTION & TRANSLATION = PROTEIN BIOSYNTHESIS