Additionally, after absorption into the blood, and after the muscle and protein retaining tissues have been saturated, excess amino acids will be oxidized and excreted as urea - meaning you will have to visit the loo. However, for one single meal the body will try to retain as much as possible, but repetetive meals with higher protein intake will increase protein oxidation. There is much in the literature about this. Often the advice is to not eat so much protein (above 2,8 grams per kg BW) as it only increases oxidation and can be unhealthy due to excess nitrogen waste products, unless you keep yourself well hydrated. Studies show that you won't see any extra mass increases because your protein intake is absurdly high. The body can only work at maximum synthesis rate.
The key to mass increase is to keep protein degradation as small as possible. Do this by increasing your physical activity, taking drugs (hazardous), or do your best to keep your natural hormones levels up (preferred). Make use of protein-sparing methods (dietary carbs and protein), and avoid going catabolic (somewhat depleted glucogen stores, high stress, long workouts, etc.).
End rant.