I'll take it one step further as well, proteins are also denatured when you chew them in your mouth 
Yes, but that is what makes the whole situation so horrible. Your body does everything it can to try to "denature" protein and make it totally unusable by the body. It's an evil evolutionary trick that tries to keep us from being able to survive. I make it a point NOT to chew, cook, or even digest my proteins. It's the only way to ensure that they're properly used in their native state.
As an analogy....crude oil is often put through horrible processes to make it high octane "gasoline" for our cars. Be wary of this practice. Only pour crude oil into your gas tank.
(To prevent further confusion, this entire post is stated in a sarcastic tone. The real emphasis is to show that the body denatures proteins during digestion, and not only is this not bad.....it improves digestibility.)