Figure 29. Digestive system.
mouth only a very short time, ptyalin does not usually have the chance to break food
particles down. Even if starch is broken down as far as maltose in the mouth, maltose
cannot be absorbed by the body in that form and must wait to be further digested by the
juices of the small intestine. The enzyme ptyalin acts on starch by the process known
as hydrolysis. Probably only 3 percent to 5 percent of the starch in the mouth is ever
hydrolyzed into maltose. Proper chewing of food greatly aids all of the digestive