BIOL 103 Study Guide - Final Guide: Gastric Acid, Mouth, Dipeptidase
28 Jul 2014
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Document Summary
Autotrophs are organisms that harvest light or chemical energy, convert it to carbon compounds and store them. Heterotrophs are organisms that get nutrients from the environment, by eating other organisms. They have evolved to have many strategies of obtaining food. Fungi are also heterotrophic, they consume dead organics matter (bread mold) or from living organic matter as parasites (athletes foot) by extending hyphae into cells and absorbing the nutrients. Intracellular digestion occurs in very simple organisms, phagocytosis lets food into the vacuoles of the cell and hydrolytic enzymes digest the food into simple monomers. It is a very slow process and you cannot store food for long periods of time. White blood cells use phagocytosis to kill microbes but some bacteria have evolved to make it more difficult. For example, pneumonia bacteria have a slippery coating on the outside. Undigested products are then excreted through the mouth. More complex organisms have more complex systems (ie. humans)
