Although RNA is a single-stranded molecule, researchers soon discovered that it can form double-stranded structures, which are important to its function.

The structure of DNA is called a double helix, which looks like a twisted staircase. Due to the base pairing, the DNA strands are complementary to each other, run in opposite directions, and are called antiparallel strands.

Perhaps the most exciting aspect of the structure of DNA deduced by Watson and Crick was, as expressed in their words, that the “specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.” A double helix separated into two single strands can be replicated because …

The double helix describes the appearance of double-stranded DNA, which is composed of two linear strands that run opposite to each other, or anti-parallel, and twist together. Each DNA strand within the double helix is a long, linear molecule made of smaller units called nucleotides that form a chain.

While DNA contains deoxyribose, RNA contains ribose, characterised by the presence of the 2′-hydroxyl group on the pentose ring (Figure 5). This hydroxyl group make RNA less stable than DNA because it is more susceptible to hydrolysis.

RNA is just a copy of the DNA that unlike the DNA travels around the cell it helps the cell do certain things and because it needs to bond with amino acids and give genetic messages it has to have one strand in order to be unstable enough to bond with other molecules.

DNA does not usually exist as a single strand, but instead as a pair of strands that are held tightly together. These two long strands coil around each other, in the shape of a double helix. The backbone of the DNA strand is made from alternating phosphate and sugar groups.

DNA is a double-stranded helix, with the two strands connected by hydrogen bonds.

DNA can form multi-stranded helices through either folding of one of the two strands or association of two, three, or four strands of DNA. In 1986, it was demonstrated that a short (15-mer) mixed-sequence triplex-forming oligonucleotide (TFO) formed a stable specific triple helical DNA complex [3].

Although usually single-stranded, some RNA sequences have the ability to form a double helix, much like DNA. Gehring said identifying the double-helical RNA will have interesting applications for research in biological nanomaterials and supramolecular chemistry.

cell nucleus

At pH 9 or higher, DNA is susceptible to alkaline denaturation due to the abundance of hydroxide ions. These negatively-charged ions remove hydrogen ions from the base pairs of DNA, thereby breaking the hydrogen bonds between and causing the DNA strands to denature.

In the pH range around the neutral pH, from pH 5 to 9, common nucleic acid duplexes are quite stable. None of the functional groups present in typical nucleic acids titrate between pH 5 to 9.

Moreover, DNA is traditionally preserved in alkaline buffers (e.g., Tris, EDTA buffer, pH 9), and will degrade if left in water due to acid hydrolysis, particularly below pH 7.515.

High pH facilitates the denaturation since it interferes with the base-pairing. High pH ( > 11.3) can be used to denature DNA.