Digestion begins in the mouth when enzymes (amylase) are secreted by salivary glands. Proteins are denatured (unfolded) in the stomach by___and digested (broken down) by___. For the stomach protein-digesting enzymes to become active, ____is needed. Given that living cells of the stomach (and everywhere else) are largely made of protein, it is amazing that they are not digested by the activity of the stomach enzymes. The most important means of stomach protection is the____it produces. The third layer of smooth muscle found in the stomach wall provides extra strength for____and mechanically breaking down food. The small intestine is protected from the corrosive action of hydrochloric acid in chyme by____, which is ducted in by the pancreas. Though small amounts are produced by in the mouth and stomach, the pancreas is the most important source of____digesting enzymes. A non-enzyme substance that assists in fat digestion is____.