Especially forming and/or breaking of chemical bonds in the direction of increased overall system stability or, alternatively, in the direction of desired progression.
To some degree the designations forward and reverse reactions can be arbitrary. When a specific product is desired or, instead, substrates are sufficiently unstable that they tend to decompose into various products, then the movements of systems towards these end points can be described as "forward" whereas movement such as of a chemical reaction in the other direction, if indeed readily achieved, can be described as a reverse reaction.
The idea of forward and reverse reactions actually are relevant only when reactions in fact are reversible. Otherwise, reactions will tend to progress only forward (though not necessarily towards only a single product).
Note that the ideas of reactant (or substrate) and product are dependent on our designating just what is the forward reaction since for the reverse reaction the designations are reversed (i.e., reactant → product but product ← reactant in the reverse direction…).
For more on this topic, see Wikipedia and Google. Contact web master. Return to home.
