BISC 101 Lecture Notes - Lecture 12: Hindgut, Semipermeable Membrane, Signal Transduction
2 Nov 2016
School
Department
Course
Professor
Document Summary
Four steps: ingestion --> digestion --> absorption --> elimination. Substrate feeders - live in or on their food source. Fluid feeders - suck nutrient-rich fluid from a living host. Suspension feeders - sift small food particles from water. Animals can obtain food in a number of ways: Bulk feeders - ingest relatively large pieces of food (most animals) Essential nutrients cannot be synthesized and must be obtained in the diet. Unsaturated fatty acids, many vitamins, minerals, coenzymes/cofactors. Digestion (food processing) occurs in specialized departments. Intercellular digestion = simplest digestive compartment: cells engulf food by phagocytosis/pinocytosis into food vacuoles where enzymes break food. Extracellular digestion = hydrolysis of food in compartments that are continuous with environment = large food can be processed, organization into specialized compartments. Linear digestive systems allow for specialization of function and continuous ingestion/digestion. Adaptations for capturing food (ingestion) - structure and function of mouthparts.
