Ribonukleinsavmolekulák

Ribonukleinsavmolekulák, commonly known as RNA molecules, are essential nucleic acid polymers crucial for various biological processes, including coding, decoding, regulation, and expression of genes. Unlike DNA, RNA typically exists as a single-stranded molecule, although it can fold into complex three-dimensional structures. The building blocks of RNA are nucleotides, each composed of a ribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and uracil (U). Uracil replaces thymine, which is found in DNA.

There are several major types of RNA, each with distinct functions. Messenger RNA (mRNA) carries genetic information transcribed from DNA to ribosomes, where it serves as a template for protein synthesis. Transfer RNA (tRNA) molecules are responsible for bringing specific amino acids to the ribosome during translation, matching them to the codons on the mRNA. Ribosomal RNA (rRNA) is a structural and catalytic component of ribosomes, the cellular machinery responsible for protein synthesis. Other non-coding RNAs, such as microRNAs (miRNAs) and small interfering RNAs (siRNAs), play critical roles in gene regulation by controlling gene expression at the post-transcriptional level. RNA molecules are synthesized through a process called transcription, where a DNA template is used to create a complementary RNA strand.