DNA, or deoxyribonucleic acid, is the molecule that carries genetic information in all living organisms. It consists of three main components that work together to form its structure. The three main components are: deoxyribose sugar, phosphate group, and nitrogenous bases. These components combine to form units called nucleotides, which are the building blocks of DNA.
Deoxyribose is a five-carbon sugar that forms the backbone of DNA. It is called deoxy because it lacks one hydroxyl group compared to ribose sugar. The deoxyribose has a five-carbon ring structure, with carbons numbered one through five. The key feature is that carbon 2 is missing its OH group, having only a hydrogen atom instead. This gives DNA its structural stability and distinguishes it from RNA.
The phosphate group is a crucial component of DNA that provides negative charge and connects nucleotides together. It contains a central phosphorus atom surrounded by four oxygen atoms. The phosphate group carries a negative three charge, making DNA an acidic molecule. One oxygen connects to the sugar, while the other oxygens carry negative charges. This creates the sugar-phosphate backbone that gives DNA its structural framework.