Thus, the total base pairs count is equal to the nucleotides count in one of the strands (including the exception of non-coding single-stranded telomeres' regions). Often, the size of either an entire genome or an individual gene of the organism is measured in the base pairs because usually, DNA is double-stranded. Particularly, this is essential in RNA molecules (for example, transfer RNA), where the Watson–Crick base pairs (adenine–uracil and guanine-cytosine) permit the formation of the short double-stranded helices, and also a wide variety of non–Watson–Crick interactions (for example, A–A or G–U) allows the RNAs to fold into a vast range of particular three-dimensional structures.Īdditionally, the base-pairing between the messenger RNA (mRNA) and transfer RNA (tRNA) forms the basis for the molecular recognition events, which result in the nucleotide sequence of the mRNA becoming translated into the amino acid sequence of proteins through the genetic code. Intramolecular base pairs can take place within the single-stranded nucleic acids. A few examples are Hoogsteen base pairs: C-G or A-T analogs. The base-pairing models of Non-Watson-Crick display alternative hydrogen-bonding patterns. In RNA, thymine is replaced by uracil (U). A bonds only with T and C bonds only with G inside the DNA molecule. The Watson crick base pairing, which is the foundation for the helical structure of double-stranded DNA, states that DNA comprises four bases: adenine (A) thymine (T) (adenine thymine) guanine (G), the two pyrimidines cytosine including guanine (C) or adenine thymine guanine cytosine. Base pairs themselves can be formed from bases that are complementary nitrogen-rich organic compounds called either pyrimidines or purines.Ĭomplementary base pairing is defined as the phenomenon where in the DNA guanine always hydrogen bonds to the cytosine and adenine binds to thymine always. Base pairs can be found in both double-stranded DNA and RNA, in which the bonds between them connect the two strands by making the possible double-stranded structures. In molecular biology, a Base pair is defined as two complementary nitrogenous molecules, which are connected by hydrogen bonds.

What are the dna base pairing rules