Now, special types of glands known as salivary glands secrete a substance of fluid known as saliva in our mouth. And saliva consists of many different things. Now, saliva consists predominantly of water. About 95% of saliva consists of water and that's because the process of hydrolysis that is catalyzed by amylase and lipase and other protein enzymes in our stomach as well as in our small intestine require water to actually break those bonds and that's why we have so much water in our saliva. Now, other components of saliva include these proteolytic enzymes, it includes glycoproteins, it includes mucus, it also includes special antibacterial molecules, enzymes such as lysozymes. These lysozymes basically attack and break down the cell walls of bacterial cells and that kills off our bacteria.