DNA, or deoxyribonucleic acid, is the molecule that carries genetic information in almost all living organisms. It is formed by the assembly of two long strands of nucleotides, which are linked together to form a double helix.
Here's how it works:
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Nucleotides are the building blocks of DNA. Each nucleotide is composed of three parts:
- A phosphate group
- A sugar group (deoxyribose)
- One of four nitrogen bases: adenine (A), guanine (G), cytosine (C), or thymine (T).
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Nucleotides link together to form a strand of DNA. The phosphate group of one nucleotide binds to the sugar group of the next nucleotide, forming a chain.
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Two DNA strands then twist around each other to form a double helix. The two strands are held together by hydrogen bonds between the nitrogen bases. Adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C). This is called complementary base pairing.
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This double helix structure provides the stability and genetic code needed for DNA to function. The sequence of nucleotides along each strand determines the genetic information that is encoded by the DNA molecule.
Therefore, the formation of DNA involves the assembly of nucleotides into strands, which then twist around each other to form the iconic double helix structure.
