Mechanical digestion which cuts, smash, and grind food increases the surface area of the food to be digested, increasing exposure to digestive juices, thus making further digestion more efficient and beneficial.
Mechanical digestion refers to the actual grinding / physical digestion in your mouth where your teeth cut and mash up your food. Chemical digestion refers to the enzymes that break up the food...
mechanical digestion - chewing, mixing, churning chemical digestion - breakdown of fat, carbohydrate and proteins by specific enzymes (lipases, amylases, and proteinases respectively)
The digestion process begins in the mouth. Chewing your food is a mechanical form of digestion. The saliva in your mouth begins to chemically break down your food, which is chemical digestion.