LIFESCI 1 Chapter Notes - Chapter 34: Mycelium, Plant Cell, Chitin
Document Summary
On land, the organisms principally responsible for the decomposition of plant and animal tissues are fungi: One of the most abundant and diverse groups of eukaryotic organisms. Fungi play a critical role in cycling carbon because of their ability to locate and break down the complex molecules and bulky tissues in plant and animal bodies. Fungi are heterotrophs, meaning that they depend on preformed organic molecules for both carbon and energy. Unlike animals, fungi do not have organs that enable them to ingest food and break it down in a digestive cavity. Instead, fungi absorb organic molecules directly through their cell walls. This mode of feeding presents two major problems. First, although simple molecules like amino acids and sugars pass readily through the cell wall, more complicated molecules do not. Fungi secrete a diversity of enzymes that break down complex organic molecules like starch or cellulose into simpler compounds that can be absorbed.
