m[[RNA]]로 부터, [[Protein]]을 합성하는 세포질([[Cytoplasm]])내의 [[Protein]]-[[RNA]]복합체. One of the CellularComponent GO:0005840 An intracellular organelle, about 200 A in diameter, consisting of [[RNA]] and [[Protein]]. It is the site of [[Protein]] biosynthesis resulting from [[Translation]] of messenger [[RNA]] (mRNA). It consists of two subunits, one large and one small, each containing only [[Protein]] and [[RNA]]. Both the ribosome and its subunits are characterized by their sedimentation coefficients, expressed in Svedberg units (symbol: S). Hence, the prokaryotic ribosome (70S) comprises a large (50S) subunit and a small (30S) subunit, while the eukaryotic ribosome (80S) comprises a large (60S) subunit and a small (40S) subunit. Two sites on the ribosomal large subunit are involved in [[Translation]], namely the aminoacyl site (A site) and peptidyl site (P site). Ribosomes from prokaryotes, eukaryotes, [[Mitochondria]], and [[Chloroplast]]s have characteristically distinct ribosomal proteins. 원핵세포 (70S Ribosome) * 50S : 5S rRNA(120b) + 23S rRNA(2904b) + 31 Proteins * 30S : 16S rRNA(1541b) + 21 Proteins 진핵세포 (80S Ribosome) * 60S : 5S rRNA + 5.8S rRNA + 28S rRNA + 50 Proteins * 40S : 18S rRNA + 30 Proteins 보통 [[Evolution]]적 연관관계의 추적을 위해 16S, 18S rRNA서열이 활용된다.