Ribonucleic acid RNA is a nucleic acid that plays a crucial role in various biological processes, including the coding, decoding, regulation, and expression of genes. The specific chemical structure of RNA consists of a long chain of nucleotide units, each composed of a sugar molecule ribose , a phosphate group, and a nitrogenous base. The nitrogenous bases in RNA are adenine A , cytosine C , guanine G , and uracil U .The structure of RNA differs from deoxyribonucleic acid DNA in several ways:1. The sugar molecule in RNA is ribose, while in DNA, it is deoxyribose. The difference between these two sugars is that ribose has an additional hydroxyl group -OH at the 2' carbon position, whereas deoxyribose has only a hydrogen atom at the same position.2. RNA is typically single-stranded, while DNA is double-stranded. This allows RNA to form various secondary and tertiary structures, such as loops, hairpins, and pseudoknots, which are essential for its function.3. The base pairings in RNA are different from those in DNA. In RNA, adenine A pairs with uracil U , and cytosine C pairs with guanine G . In DNA, adenine A pairs with thymine T , and cytosine C pairs with guanine G .The structure of RNA contributes to its function within the cell in several ways:1. The single-stranded nature of RNA allows it to fold into various structures, which are essential for its function in catalysis, binding, and recognition. For example, transfer RNA tRNA adopts a cloverleaf structure that is crucial for its role in protein synthesis.2. The presence of the hydroxyl group at the 2' carbon position in ribose makes RNA more reactive and less stable than DNA. This is advantageous for RNA's role as a transient carrier of genetic information, as it can be easily degraded and recycled within the cell.3. The different base pairings in RNA allow it to form complementary base pairs with DNA during transcription, which is the process of copying genetic information from DNA to RNA. This is essential for gene expression and regulation.Overall, the unique chemical structure of RNA enables it to perform various functions within the cell, such as carrying genetic information, catalyzing biochemical reactions, and regulating gene expression.