Which of the following body systems breaks down proteins into amino acids

When protein enters the stomach, it begins to break down thanks to tiny glands  of the stomach which produces juices to help digest food, but only when it enters the small intestine does the protein molecules break down into amino acids.

So the Small Intestine is the answer.

Have a great day! :)

The equator absorbs the most sunlight

Predator instincts is what causes it