Answer:Intermediates of a multistep reaction sequence do not dissociate from the enzyme complex.
Explanation:
Substrate channeling is the moving of intermediate metabolic product of one enzyme to another enzyme without it be lost to another enzyme.
Channeling makes metabolic pathway more fast and efficient that it will be when the enzyme are at random.
It avoid the use up of intermediate formed by other reaction catalyze by another enzyme.
For pyruvate dehydrogenase channeling prevent the intermediate from dissolving and been used up by other reaction.