Strategies of digestion and defecation

Richard M. Sibly

Most prey erect defences that make them harder to digest, because it pays them (usually) to be less profitable food. Cracking these defences is the first objective of digestion, and is achieved by chewing, grinding in a gizzard, chemical or microbial attack. When these defences are breached and the food cells have been separated into their constituents, enzymes break down the bonds the formed, for example, a protein from amino acids. The amino acids are then transported across the gut wall. The process of digestion is complete when all the food has been broken down into components small enough to be absorbed across the gut wall into the blood.

Fonte: Sibly, R. M. 1981. In: Townsend, C. R. & Calow,P., eds. Physiological ecology: An evolutionary approach to resource use. Oxford, Blackwell.