Catalytic triadA catalytic triad is a set of three coordinated amino acids that can be found in the active site of some enzymes. Catalytic triads are most commonly found in hydrolase and transferase enzymes (e.g. proteases, amidases, esterases, acylases, lipases and β-lactamases). An acid-base-nucleophile triad is a common motif for generating a nucleophilic residue for covalent catalysis. The residues form a charge-relay network to polarise and activate the nucleophile, which attacks the substrate, forming a covalent intermediate which is then hydrolysed to release the product and regenerate free enzyme.
ModernityModernity, a topic in the humanities and social sciences, is both a historical period (the modern era) and the ensemble of particular socio-cultural norms, attitudes and practices that arose in the wake of the Renaissancein the Age of Reason of 17th-century thought and the 18th-century Enlightenment. Some commentators consider the era of modernity to have ended by 1930, with World War II in 1945, or the 1980s or 1990s; the following era is called postmodernity.
