RNAmolecuul

RNAmolecuul, or RNA molecule, is a polymer composed of nucleotides that forms ribonucleic acid. Each nucleotide contains a ribose sugar, a phosphate group, and a nitrogenous base (adenine, uracil, guanine, or cytosine). RNA typically exists as a single strand and folds into complex three-dimensional structures through intramolecular base pairing, though some RNAs adopt duplex or highly structured configurations. The 2'-hydroxyl group on the ribose makes RNA more chemically reactive and less stable than DNA, contributing to its dynamic role in cells.

RNA molecules are synthesized in cells by RNA polymerases using a DNA template in a process called transcription. Some RNA can also be produced by RNA-templated replication in RNA viruses. RNA plays multiple roles: messenger RNA (mRNA) carries genetic information from DNA to ribosomes for protein synthesis; transfer RNA (tRNA) delivers amino acids; ribosomal RNA (rRNA) is a structural and catalytic component of ribosomes; small RNAs (miRNA, siRNA, piRNA) regulate gene expression; and other long non-coding RNAs participate in regulation and scaffolding. Some RNA molecules act as enzymes (ribozymes) that catalyze chemical reactions.

RNA molecules fold into secondary structures such as stems, loops, bulges, and pseudoknots that determine their function. Base pairing follows A with U and G with C, with wobble interactions adding complexity. RNA can be chemically modified (for example, methylation or pseudouridylation) which affects stability and function. In cells, RNases rapidly degrade RNA; however, stable RNAs can persist long enough to perform their roles.

RNA molecules are central to biology and biotechnology. They translate genetic information, regulate gene expression, and can be engineered for therapeutic purposes, including mRNA vaccines and RNA interference technologies. Ongoing research explores synthetic biology approaches using RNA for sensors, circuits, and therapeutic agents.