Ribosomes are ribonucleoprotein complexes composed of RNA and proteins, which have two main roles 1-decode the message of the messenger RNA (mRNA) molecule and the formation of peptide bonds in the protein. For this purpose, each triplet of nucleotide bases or 'codon' in the mRNA sequence is used to assemble specific amino acids in the nascent polypeptide chain. Although different, both prokaryotic ribosomes and eukaryotic ribosomes are composed of two subunits: one small subunit that decodes the mRNA into a specific amino acid chain, and one large subunit that forms the peptide bonds in the polypeptide chain. Each ribosomal subunit is in turn composed of ribosomal RNAs and proteins. These ribosomal RNAs act as scaffolds by combining with proteins that assemble into ribosomes (i.e., small and large ribosome subunits).
Mutations are random Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not “try” to supply what the organism “needs.”
