Nënnukleotideve

Nënnukleotideve, or nucleotides, are the basic building blocks of nucleic acids, which include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Each nucleotide is composed of three main components: a phosphate group, a five-carbon sugar (either deoxyribose in DNA or ribose in RNA), and a nitrogenous base. The nitrogenous bases are divided into two categories: purines, which include adenine (A) and guanine (G), and pyrimidines, which include cytosine (C), thymine (T, found only in DNA), and uracil (U, found only in RNA).

The sequence of these nucleotides along a nucleic acid chain carries the genetic information. In DNA, adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C) through hydrogen bonds, forming the double helix structure. In RNA, uracil pairs with adenine (U-A), and guanine pairs with cytosine (G-C). This specific pairing is crucial for DNA replication and transcription, the processes by which genetic information is copied and transferred.

Beyond their role in genetic material, nucleotides also serve as energy currency in cells, most notably in the form of adenosine triphosphate (ATP). ATP is generated during cellular respiration and provides the energy required for numerous biological processes. Furthermore, nucleotides are involved in cell signaling and act as coenzymes in various metabolic reactions. The fundamental structure and versatile functions of nucleotides make them essential molecules for all known forms of life.