DNA

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Deoxyribonucleic acid (DNA) is a significant macromolecule in living organisms, forming a double helix that holds genetic instructions for growth, development, functioning, and reproduction. Composed of two polynucleotide chains, DNA is made up of nucleotides containing nitrogen-containing bases (cytosine, guanine, adenine, or thymine), deoxyribose sugar, and a phosphate group. The nucleotides are bonded together by the sugar and phosphate of adjacent units, forming a sugar-phosphate backbone. The nitrogenous bases pair according to specific rules (A with T, C with G) via hydrogen bonds to create double-stranded DNA. Non-coding sections make up more than 98% of human DNA, and the two DNA strands run in opposite directions along the antiparallel backbone, which encodes genetic information. RNA is transcribed from DNA for protein synthesis during translation. Eukaryotic cells organize DNA into chromosomes, while prokaryotes store their DNA in the cytoplasm. Chromatin proteins help compact and organize DNA within eukaryotic chromosomes. First isolated by Friedrich Miescher in 1869, Watson and Crick identified DNA's molecular structure in 1953. Its unique properties have made it a valuable tool for research, material science, and engineering applications.