PP

A coupled reaction is a series of connected reactions that share products and substrates. The reactions increase efficiency of energy transfer, and allows more points of regulation. The regulation is important for conservation of energy and resources for the cell. In order for a coupled reaction to be favorable, the net delta G must be overall negative. This means the pathways cannot be direct opposites of each other because than the pathway would have a slightly positive making it unfavorable. Also the pathway would then be futile and waste energy.