1. A phosphate group: This is a negatively charged group containing phosphorus and oxygen atoms.
2. A five-carbon sugar: This can be either ribose (in RNA) or deoxyribose (in DNA).
3. A nitrogenous base: There are five different nitrogenous bases found in nucleic acids:
* Adenine (A)
* Guanine (G)
* Cytosine (C)
* Thymine (T) (found only in DNA)
* Uracil (U) (found only in RNA)
These nucleotides are linked together in a chain through phosphodiester bonds between the phosphate group of one nucleotide and the sugar of the next. This forms the backbone of the nucleic acid, with the nitrogenous bases extending outwards.
The sequence of nitrogenous bases along the nucleic acid chain is what carries the genetic information. In DNA, the bases pair up in a specific way: adenine (A) always pairs with thymine (T), and guanine (G) always pairs with cytosine (C). This pairing is based on hydrogen bonding between the bases. In RNA, adenine (A) pairs with uracil (U), and guanine (G) still pairs with cytosine (C).
So, in summary, nucleic acids are made up of chains of nucleotides, each of which is composed of a phosphate group, a sugar, and a nitrogenous base.
