Nucleic acid double helixIn molecular biology, the double helix is the structure formed by double-stranded molecules of nucleic acids such as DNA. The double-helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The DNA double-helix biopolymer of nucleic acids is held together by nucleotides which base pair together.
Nucleic acid tertiary structureThe image above contains clickable linksInteractive image of nucleic acid structure (primary, secondary, tertiary, and quaternary) using DNA helices and examples from the VS ribozyme and telomerase and nucleosome. (PDB: ADNA, 1BNA, 4OCB, 4R4V, 1YMO, 1EQZ)Nucleic acid tertiary structure is the three-dimensional shape of a nucleic acid polymer. RNA and DNAmolecules are capable of diverse functions ranging from molecular recognition to catalysis.
Nucleic acid secondary structureNucleic acid secondary structure is the basepairing interactions within a single nucleic acid polymer or between two polymers. It can be represented as a list of bases which are paired in a nucleic acid molecule.
DNADeoxyribonucleic acid (pronunciation; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids.
HelixA helix (; pl.helices) is a shape like a cylindrical coil spring or the thread of a machine screw. It is a type of smoothskew curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word helix comes from the Greek word ἕλιξ, "twisted, curved".
James WatsonAmerican biologist (1928–2025)James Dewey Watson (April 6, 1928 – November 6, 2025) was an American molecular biologist, geneticist, and zoologist. In 1953, James Watson and Francis Crick co-authored an academic paper on DNA entitled, "Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid".
Base pairA base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA.
Nucleic acidNucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is deoxyribose, a variant of ribose, the polymer is DNA.
Molecular biologyMolecular biology is a branch of biology that seeks to understand the molecular structures and chemical processes that are the basis of biological activity within and between cells. It is centered largely on the study of nucleic acids (such as DNA and RNA) and proteins.
NucleotideNucleotides are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acidpolymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver.
BiopolymerBiopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The polynucleotides, RNA and DNA, are long polymers of nucleotides.
Chirality (chemistry)In chemistry, a molecule or ion is called chiral () if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality (). The terms are derived from Ancient Greek (cheir) 'hand'; which is the canonical example of an object with this property.*As an Amazon Associate I earn from qualifying purchases.