Nutrition Nutrition The way in which living organisms

Nutrition

Nutrition The way in which living organisms obtain energy and the raw materials from which they build up their organic compounds from inorganic ones – the raw materials are obtained from nutrients. There are two main modes of nutrition Autotrophic Heterotrophic Photosynthesis? Holozoic feeders Chemosynthesis? Saprophytic feeders Parasitic feeders Symbiotic/mutualistic feeders 2

What Is An Autotroph? An organism that can manufacture its own organic compounds from inorganic materials. Autotroph Photoautotroph Uses light as an energy source to synthesise organic compounds from inorganic compounds Photosynthesis Chemoautotroph Uses energy derived from chemical reactions involving inorganic compounds to make organic compounds Chemosynthesis 3

Photoautotrophic Nutrition Photosynthesis 4

Chemoautotrophic Nutrition Chemosynthesis Rhizobium Nitrifying bacteria 5

Heterotrophic Nutrition Holozoic feeders 6

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Saprophytic feeders 8

Different Digestive Systems – A Summary 9

Hydra A simple tube gut with no specialized regions Digestive - The cells of the gastrodermis secrete digestive juices that pour into a central cavity. The enzymes begin the digestive process, which is completed within food vacuoles when small pieces of the prey are engulfed by the cells of the gastrodermis 10

Sponges 11

Sponges are sessile filter feeders. This means that they remain in one place as an adult, and the food they acquire filters through the pores. Microscopic food particles brought by the water are engulfed by the collar cells and are digested by them in food vacuoles or they are passed to the amoeboid cells for digestion. 12

A tube gut with specialized regions An Insect An Earthworm 13