What is DNA made of?

DNA (Deoxyribonucleic Acid) is a complex molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It is made up of smaller units called nucleotides. Each nucleotide consists of three components:

1. Sugar: The sugar in DNA is deoxyribose, which is a five-carbon sugar. It differs from ribose (found in RNA) by having one less oxygen atom.
2. Phosphate Group: Each nucleotide contains a phosphate group, which is made of a phosphorus atom bound to four oxygen atoms. The phosphate groups link the sugar molecules of adjacent nucleotides, forming the “backbone” of the DNA strand.
3. Nitrogenous Base: DNA has four types of nitrogenous bases, which are the building blocks of the genetic code. These bases are divided into two categories:
   • Purines: Adenine (A) and Guanine (G)
   • Pyrimidines: Cytosine (C) and Thymine (T)

Structure of DNA:

DNA is a double-stranded helix. The two strands run in opposite directions and are held together by hydrogen bonds between the complementary nitrogenous bases:

• Adenine (A) pairs with Thymine (T).
• Cytosine (C) pairs with Guanine (G).

The two strands of DNA twist into a helical shape, forming the well-known double helix structure.

DNA is made of nucleotides, each consisting of a sugar (deoxyribose), a phosphate group, and a nitrogenous base. The sequence of these nitrogenous bases encodes genetic information, and the two complementary strands of DNA are held together by base pairs, forming the double-helix structure. This structure allows DNA to store and transmit genetic information across generations.