Forms Of Heterotrophic Nutrition And Feeding Mechanisms

Introduction

                  Nutrition is the process of obtaining nutrients from food by organisms in order to maintain life. These nutrients are important for various metabolic reactions, which occur in organisms for the synthesis of biomolecules for growth, repair and to provide energy.

                         The method by which an organism obtains food is referred to as the mode of nutrition. It is a known fact that, organisms either synthesize their own food or consume food prepared by other organisms. According to the mode of nutrition organisms are broadly classified in to two categories, Autotrophic organisms and Heterotrophic organisms.

               Autotrophic (self-Feeding) organisms manufacture their own food ( The Organic compounds) from inorganic raw materials ( carbon dioxide and water) obtained from the environment. Autotrophs can further divide into two groups according to their source of energy, Photoautotrophs and Chemoautotrophs. Radiant energy from the light is essential for photosynthesis while the chemosynthesis utilize the energy obtained from the chemical oxidation of simple inorganic compounds such as iron, sulphur and ammonium ions.

                          In Contrast to autotrophs, heterotrophic organisms are unable to synthesize their own food. Therefore, heterotrophs utilize preformed food with complex organic substances (organic carbon compounds) for their nutrition. There are three main categories of heterotrophic nutrition, which you will be learning in the section ' main categories of heterotrophic nutrition'.

                          Due to the utilization of performed food, heterotrophs need to take them into their body using a feeding mechanism. The next section of the session deals with the ' feeding mechanisms in heterotrophic animals '. Here, we will be dealing mainly with the feeding mechanisms of holozoic animals, as it is the group which shows variety of adaptions. You do not find any feeding mechanisms in saprophytes as they absorb digested food through their body surface. Depending on the type of food they eat, parasites show feeding mechanisms and adaptions for feeding.