Digestion

• Intracellular digestion occurs in porifera using the beating flagella of choanocytes to draw a current of water in through porocytes
• Extracellular digestion is the breakdown of food outside cells and occurs within compartments that are continuous with the outside of the animal's body, allowing digestion of larger prey
• Many simple animals have a digestive sac with a single opening known as a gastrovascular cavity. It functions both in digestion and distribution of nutrients throughout the body
• Most animals have an alimentary canal; a digestive tube extending between two openings, a mouth and anus.
• Macromolecules can be broken down by hydrolysis
• Enzymes are specialised proteins that catalyse chemical reactions in biological systems
• Carnivore adaptations include pointed incisors and canines to kill and rip, jagged premolars / molars to crush and shred
• Herbivore adaptations include broad ridged surfaces to grind tough plant material, incisors and canines modified for biting vegetation, potential lack of canines, and gap in dentition
• Omnivores have teeth adapted for both vegetation and meat
• Long intestines aids in the processing of fibrous protein from eucalyptus
• The caecum functions as a fermentation chamber
• Symbiotic bacteria convert shredded leaves to more easily digested food
• Cows have 4 stomachs