Here's a breakdown of a nucleotide's components:

* Phosphate group: A negatively charged group containing phosphorus.

* Sugar: A five-carbon sugar. In RNA, the sugar is ribose. In DNA, the sugar is deoxyribose.

* Nitrogenous base: A molecule containing nitrogen that can form hydrogen bonds with other bases. There are five main nitrogenous bases:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T) (found only in DNA)

* Uracil (U) (found only in RNA)

These three components are joined together in a specific way to form a nucleotide.

Nucleotides link together to form long chains called polynucleotides. The phosphate group of one nucleotide binds to the sugar of the next nucleotide, creating a sugar-phosphate backbone. The nitrogenous bases stick out from this backbone and can form hydrogen bonds with complementary bases on other polynucleotide strands. This is the basis of DNA's double helix structure and RNA's various structures.