Now, mechanical digestion is the process by which we break down the large food particles into much smaller food particles. Now, mechanical digestion does not actually break down any chemical bonds. It does not break any covalent bonds that actually hold those macromolecules together. What it actually does is it simply increases the surface area of the food on which the proteolytic enzymes found in the mouth, in our stomach and small intestine can actually act on. And this makes the process of digestion the breakdown much more efficient and effective. Now, what actually initiates and creates mechanical digestion is the movement of the muscles and the teeth found inside our mouth.