Nutrition• Process by which organisms obtain and use the nutrients required for maintaining life
Modes of nutrition• Ways of obtaining and using nutrients Nutrition Autotrophic Heterotrophic nutrition nutrition Holozoic Saprophytic Parasitic nutrition nutrition nutrition
Autotrophic nutrition• make their own food (complex organic substances) using simple inorganic substances – the organism autotrophs• e.g. Green plants – by photosynthesis
Heterotrophic nutrition• depends on other organisms or dead organic matters as their food sources – the organism Heterotrophs• Cannot make their own food and obtain their food in organic form
Autotrophic nutrition• PHOTOAUTOTROPHS CHEMOAUTOTROPHS Photosynthetic organisms Deriving energy are photoautotroph which from chemical reactions, means that they are synthesize all necessary repositories of energy, they organic compounds are able to synthesize food from carbon dioxide. directly from carbon dioxide, eg- bacteria water, and using energy from light.
Other modes of nutrition in plants• Parasitic• Insectivorous• Saprophitic• symbiotic
Saprophytic nutrition (Saprophytism)• Organisms feed on dead organisms or non- living organic matter – Saprophytes (e.g. fungi, bacteria)
How A Saprophyte Obtains Its Nutrients? Example : Mucor & Rhizopus (bread mould)• • Mass of hyphae = are • Digestedrelease Hyphae products Enzymes digest Sporangium enzyme into : produces digestiveby hyphae mycelium organic absorbed complex sporesbread the for reproduction molecules in bread into simple, soluble molecules (extracellular digestion )
Importance of saprophytes • As decomposers – Allow essential materials (e.g. C, N) to be recycled in the ecosystem Enzyme fromComplex organic saprophytes Simple soluble substances compounds
Why is it necessary to leave the moist breaduncovered for 30 minutes ?Ans: Because the spore of Mucor are carried by air current. They can drop onto the bread and then germinate.
What are the thread-like structures growing on thesurface of the bread ?Ans: The thread-like structures are used for feeding. They are called hyphae which can produce enzymes for digesting the organic food.