Polynukleotidiketjua

Polynukleotidiketjua refers to a polynucleotide chain, which is a long chain of nucleotides. Nucleotides are the basic building blocks of nucleic acids, such as DNA and RNA. Each nucleotide consists of three parts: a phosphate group, a pentose sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base. These nitrogenous bases are adenine (A), guanine (G), cytosine (C), thymine (T) in DNA, and adenine (A), guanine (G), cytosine (C), and uracil (U) in RNA.

In a polynucleotide chain, the nucleotides are linked together by phosphodiester bonds. These bonds form between the phosphate group of one nucleotide and the sugar of the next nucleotide, creating a sugar-phosphate backbone. The sequence of these nitrogenous bases along the chain carries the genetic information. DNA typically exists as a double-stranded helix, where two polynucleotide chains are held together by hydrogen bonds between complementary bases (A with T, and G with C). RNA, on the other hand, is usually single-stranded, although it can fold upon itself to form complex three-dimensional structures. The order and composition of nucleotides in a polynucleotide chain are critical for its function in biological processes, including heredity, protein synthesis, and gene regulation.