FATS leave your stomach more slowly than either carbohydrates or proteins, very little fat digestion occurs in the stomach. Bile from the liver prepares fat for the breakdown by emulsifying it, making it soluble in water. Emulsification makes it easier for enzymes to break the fat into smaller pieces for digestion. In the small intestine, the pancreatic enzyme lipase splits fats into fatty acid and glycerol, which your body then absorbs.............PROTEIN breakdown occurs mostly in the stomach, where stomach acids uncoil the protein strands. Pepsin, an enzyme secreted by the stomach, breaks the strands down further. Trypsin, another enzyme, splits the protein strands into molecules containing one, two or three amino acids in the small intestine. Nearly all the protein in foods is digested, with the remainder passing through the large intestine. ........... CARBOHYDRATES breakdown begins in the mouth, as enzymes and the mechanical act of chewing start to break them down before they even reach your stomach. Although carbohydrate breakdown continues in the stomach, most carbohydrates, with the exception of alcohol, are absorbed in the small intestine. Your body can only absorb simple sugars. Cells that line the small intestine secrete enzymes that break complex carbohydrates down into simple sugars..........

Yes as saliva has amylase enzyme which convert all polysaccharides into di and trisaccharides Fats doesn't start at mouth it start at stomach by action of gastric lipase