7.3.4 DNA & Natural Polymers

• DNA is formed of two long polymer chains, built out of the combination of four types of monomers called nucleotides. These two polymer chains are wrapped around each other in a structure known as the double helix (discovered by Rosalind Franklin in 1953).

The function of DNA:

• Base Pairs: The two strands of DNA are held together by bonds between pairs of nitrogenous bases, which are often referred to as base pairs. There are four bases in DNA—adenine (A), thymine (T), cytosine (C), and guanine (G). Adenine pairs with thymine, and cytosine pairs with guanine.
• Genetic Code: The sequence of these base pairs forms the genetic code. This code contains the instructions that cells use to build proteins, which are essential for life processes.

Other Natural Polymers:

• Starch: A polymer made from glucose molecules, used by plants to store energy.
• Cellulose: Another polymer of glucose, which forms the cell walls of plants and provides structural support.