Nukleotidiketjun

Nukleotidiketju refers to a linear sequence of nucleotides. Nucleotides are the basic building blocks of nucleic acids, such as DNA and RNA. Each nucleotide consists of three components: a nitrogenous base, a five-carbon sugar (deoxyribose in DNA, ribose in RNA), and one or more phosphate groups. The bases in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T), while RNA uses adenine (A), guanine (G), cytosine (C), and uracil (U) instead of thymine.

These nucleotides link together through phosphodiester bonds, forming a chain. In DNA, two such chains form a double helix, with the bases paired specifically: A with T, and G with C. This pairing is crucial for DNA replication and transcription. In RNA, the chains are typically single-stranded, although they can fold upon themselves to form complex three-dimensional structures. The sequence of nucleotides in a nucleic acid chain carries genetic information. This sequence dictates the order of amino acids in proteins, which in turn perform a vast array of functions within living organisms. Understanding the structure and sequence of nucleotide chains is fundamental to molecular biology and genetics.