It is difficult to prepare an amide from a carboxylic acid and an amine directly, since an acid-base reaction occurs which renders the amine nitrogen non-nucleophilic. Typically, in such an amide synthesis, the carboxylic acid OH group is first transformed into a better, nonacidic leaving group. In practice, amides are often prepared by treating the carboxylic acid with dicyclohexylcarbodiimide (DCC). The amine is then added and nucleophilic acyl substitution occurs easily because dicyclohexylurea is a good leaving group. This method of amide bond formation is a key step in the laboratory synthesis of peptide bonds (amide bonds) between protected amino acids. Draw curved arrows to show the movement of electrons in this step of the mechanism.

Description: biological systems 5 differ from chemical systems when it comes to equilibrium. in a chemical system once equilibrium is met, no other reactions occur. in a biological system, a dynamic equilibrium is used when a substrate is turned into a product, another reaction creates the same substrate thus keeping the concentrations stagnant. this allows for cells to continually make new compounds without messing the delta g for the systems instructions: write a response to the following prompt and then respond to your peers. your individual response is due thursday at midnight (cst) your response to your peers is due saturday at midnight (cst) prompt: propose what would happen if a living cell all the sudden reached chemical equilibrium. also discuss the effects of build up of a particular substrate on a biological system. how would this affect overall delta g's?