Question

Why is ssDNA required for DNAp?

Answer 1

DNA:

1. DNA is a polymer made up of two polynucleotide chains which coil around each other and form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all organisms.
2. It exists in two forms – single-stranded (ssDNA) or double-stranded (dsDNA).

ssDNA:

1. ssDNA can fold into different shapes but is usually stellate or star-shaped, while the dsDNA exists in double helixes in which two strands of DNA wind around each other.
2. During DNA partition (DNAp), an enzyme called helicase unwinds the dsDNA and opens a replication fork from where the two strands of parental DNA gets separated.
3. Single-strand binding proteins present in the ssDNA attaches to the two DNA strands and prevents them from reannealing.
4. Also, the synthesis of ssDNA during DNA replication allows the duplication of genetic material leading to the reproduction of cells.
5. SsDNA also provide aid with DNA repair as dsDNA can get damaged by external factors like free radicals and radiation.