Related words. 1  post verb. 2  post up phrasal verb. 3  post off phrasal verb.  cross-post 1  verb. 1. a public notice, especially one advertising a job Synonyms and related words. Types of advertisement:ad, advert, advertisement...  2. a job that someone is sent somewhere to do, usually in another country Synonyms and related words.
Catalytic RNAs, or ribozymes, are a fossil record of the ancient molecular evolution of life on Earth and still provide the essential core of macromolecule synthesis in all life forms today.
A ribozyme is a polyribonucleotide (RNA molecule) with enzymatic activity. They are sometimes also referred to as RNA enzymes however, to avoid confusion with ribonucleoproteins in which the RNA lacks catalytic activity, ribozyme is generally preferred. Ribozymes have been found in every known cell and are essential to cell functioning. The most well known example of an essential ribozyme is the 28S rRNA (called the 23S rRNA in prokaryotes), which carries out the aminoacyltransferase (peptide-lengthening) activity of ribosomes.