The digestive system is made up of key parts, each of which has a different function. Food passes through most of these parts in a journey from the mouth to the anus.

The mouth is where digestion begins, and it breaks down food into smaller particles. Read more about the functions and biological structure of the mouth.

“That also means it doesn’t like to crystallize,” she said. This is problematic for the classic method used to study enzymatic structure, known as x-ray crystallography, which requires solid crystal ...