Ribosome

A ribosome is a complex molecular machine found in all living cells that serves as the site of biological protein synthesis. Ribosomes read the genetic messenger RNA (mRNA) and translate it into a specific sequence of amino acids, which then fold into functional proteins. They consist of two subunits, one large and one small, each composed of ribosomal RNA (rRNA) and proteins. In prokaryotic cells, ribosomes are smaller (70S) while in eukaryotic cells they are larger (80S). Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum, forming rough ER. During protein synthesis, ribosomes move along the mRNA strand, reading codons and facilitating the attachment of corresponding amino acids carried by transfer RNA (tRNA). The process continues until a stop codon is reached, at which point the completed protein is released. Ribosomes are essential for life as they are responsible for producing the proteins that carry out most cellular functions.