Explore Related Concepts

autotrophic mode of nutrition

Best Results From Wikipedia Yahoo Answers


From Wikipedia

Autotroph

An autotroph, also called a producer, is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple inorganic molecules using energy from light (by photosynthesis) or inorganic chemical reactions (chemosynthesis). They are the producers in a food chain, such as plants on land or algae in water. They are able to make their own food and can fix carbon. Therefore, they do not utilize organic compounds as an energy source or a carbon source. Autotrophs can reduce carbon dioxide (add hydrogen to it) to make organic compounds. The reduction of carbon dioxide, a low-energy compound, creates a store of chemical energy. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide. An autotroph converts physical energy from sun light (in case of green plants) into chemical energy in the form of reduced carbon.

Autotroph can be phototrophs or lithotrophs (chemoautotrophs). Phototrophs use light as an energy source, while lithotrophs oxidize inorganic compounds, such as hydrogen sulfide, elemental sulfur, ammonium and ferrous iron. Phototrophs and lithotrophs use a portion of the ATP produced during photosynthesis or the oxidation of inorganic compounds to reduce NADP+ to NADPH in order to form organic compounds.

Ecology

Autotrophs are fundamental to the food chains of all ecosystems in the world. They take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called primary production. Other organisms, called heterotrophs, take in autotrophs as food to carry out functions necessary for their life. Thus, heterotrophs — all animals, almost all fungi, as well as most bacteria and protozoa— depend on autotrophs for the energy and raw materials they need. Heterotrophs obtain energy by breaking down organic molecules (carbohydrates, fats, and proteins) obtained in food. Carnivorous organisms ultimately rely on autotrophs because the nutrients obtained from their heterotroph prey come from autotrophs they consumed.

Variants

Some organisms rely on organic compounds as a source of carbon, but are able to use light or inorganic compounds as a source of energy. Such organisms are not defined as autotrophic, but rather as heterotrophic. An organism that obtains carbon from organic compounds but obtains energy from light is called a photoheterotroph, while an organism that obtains carbon from organic compounds but obtains energy from the oxidation of inorganic compounds is termed achemoheterotrophor chemolithoheterotroph.

Evidence suggests that some fungi may also obtain energy from radiation. Such radiotrophic fungi were found growing inside a reactor of the Chernobyl nuclear power plant.

Flowchart

  • Autotroph
    • Chemoheterotroph
    • Photoheterotroph


From Yahoo Answers

Question:r they considered as a mode of nutrition such as autotrophic or heterotrophic? or they just a type of organism?

Answers:Saprophytes are organisms that feed on dead and decaying organic matter.They're heterotrophic. They digest the food outside their bodies by breaking it down with the help of enzymes released by them and then absorb the good. Examples are different types of fungi such as bread mould,mushroom etc.

Question:what is the difference between an autotroph and a heterotrph? Describr the source or energy each relies upon.

Answers:Greek autos = self and trophe = nutrition) is an organism that produces complex organic compounds from simple inorganic molecules and an external source of energy, such as light or chemical reactions of inorganic compounds. Autotrophs are considered producers in a food chain. Plants and other organisms that carry out photosynthesis are phototrophs (or photoautotrophs). Bacteria that utilize the oxidation of inorganic compounds such as hydrogen sulfide, ammonium or ferrous iron as an energy source are chemoautotrophs (some are known as lithotrophs). Autotrophs are a vital part of the food chains of all ecosystems. They take energy from the environment (sunlight or inorganic sources) and use it to process carbon-based and other organic molecules that are used to carry out various biological functions such as cell growth. Other organisms, called heterotrophs, utilize autotrophs as food to carry out these same functions. Thus, heterotrophs animals, fungi, as well as most bacteria and protozoa depend on autotrophs for both energy and raw materials to make complex organic molecules. This mechanism is called primary production in the sea. Heterotrophs obtain energy by breaking down organic molecules obtained in food. Carnivorous animals ultimately rely on autotrophs because the energy and organic building blocks obtained from their prey comes from autotrophs they preyed upon. There are some species of organisms that require organic compounds as a source of carbon, but are able to use light or inorganic compounds as a source of energy. Such organisms are not defined as autotrophic, but rather as heterotrophic. An organism that obtains carbon from organic compounds but obtains energy from light is called a photoheterotroph, while an organism that obtains carbon from organic compounds but obtains energy from the oxidation of inorganic compounds is termed a chemoheterotroph. A heterotroph (Greek heterone = (an)other and trophe = nutrition) is an organism that requires organic substrates to get its carbon for growth and development. A heterotroph is known as a consumer in the food chain. Contrast with autotrophs which use inorganic carbon dioxide or bicarbonate as sole carbon source. All animals are heterotrophic, as well as fungi and many bacteria. Some parasitic plants have also turned fully or partially heterotrophic, whereas carnivorous plants use their flesh diet to augment their nitrogen supply, but are still autotrophic. Heterotrophs are unable to synthesize organic, carbon based compounds independently from the inorganic environment's sources (e.g. Animalia, unlike Plantae, cannot photosynthesize) and therefore must obtain their nutrition from another heterotroph or an autotroph. For a species to be termed a heterotroph, it must obtain its carbon from organic compounds. If it obtains nitrogen from organic compounds, but not energy, it will be deemed an autotroph. If a species obtains carbon from organic compounds then there are two possible subtypes of these heterotrophs: * photoheterotroph obtains energy from light and must obtain carbon in an organic form * chemoheterotroph obtains energy from the the consumption of organic molecules and an organic form of carbon In simpler terminology, a heterotroph is an organism that is incapable of making its own food from light or inorganic compounds, and feeds on organisms or the remains of other organisms to get its necessary energy to survive.

Question:There's a follow-up question after this: What is the comparison and contrast between the structures, nutrition and reproduction of the 5 kingdoms ( Monera, Protoctista, Fungi, Animalia, Plantae)? Please reply A.S.A.P. Thanks for helping.

Answers:The five-kingdom classification of organisms Nomenclature: Naming of organisms Binomial: Biological name of an organism Genus species Taxon: Set of organisms within a category / Taxonomy / Study of biological classification Different levels of taxons: SPECIES, GENUS, FAMILY, ORDER, CLASS, PHYLUM, KINGDOM Most number of species on right Most similar organisms on left Unicellular: Single cell; Colonial: Groups of cells; Multicellular: Many cells Autotrophs produce energy from inorganic sources Phototrophs from photosynthesis/sunlight Chemotrophs from simple inorganic (oxidative) processes Heterotrophs digest and absorb organic molecules Prokaryotae (prokaryotes) Cell structure: Prokaryotes, unicellular Prokaryotes lack cytoplasmic organelles found in eukaryotes Cell wall: murein Nutrition: autotrophic (photosynthesis, chemosynthesis), aerobic heterotrophs Divide by binary fission, not by mitosis 10 m in size (bacterial cell, filaments of blue-green bacteria) Mutualistic nitrogen-fixing bacteria live in nodules on the root of legumes / symbiotic Protoctista (protoctists) Cell structure: eukaryotes, unicellular and multicellular Cell wall: (sometimes) polysaccharide Nutrition: autotrophic, heterotrophic Placed in this category by exclusion / cannot be placed in any other kingdom Slime moulds / fungi characteristics Protozoa / heterotrophic and ingest food Algae / photosynthesis 10 m (amoeba) - 1m (Laminaria / large brown alga) Fungi Cell structure: eukaryotes, multicellular and unicellular (yeast) Cell wall: chitin Nutrition: heterotrophic / saprotrophic decomposers or parasitic Genus Penicillium Body of a fungus is composed of thin filaments called hyphae / form a mycelium Secret enzymes / external digestion / absorbs resulting nutrients Erect hyphae that grow upwards from the mycelium carry their reproductive spores Chains of spores on the erect hyphae / coloured mould visible on stored food Break down organic matter Plantae (plants) Cell structure: only multicellular, eukaryotic; large vacuoles Cell wall: cellulose Nutrition: autotrophic (photosynthetic) Growth is restricted to meristems (layers/patches of dividing cells) Non-motile; adapted to land / strong tissues, leave gas exchange system, waterproofed Eg mosses, ferns, conifers, angiosperms (flowering plants) Plant kingdom has two different types of adults in their life cycle Gametophytes, hidden in plant / sexual reproduction forms multicellular zygotes Sporophytes, what we call plant / asexual reproduction to form spores that germinate into gametophytes Gametophyte (n) gamete (n) fertilisation zygote (2n) mitosis sporophyte (2n) meiosis spore (n) mitosis gametophyte (n) Animalia (humans, animals) Cell structure: eukaryotic, multicellular, no cell wall Develop form a blastocyst / embryo Have nervous and hormonal control systems No cell wall! Nutrition: heterotrophic, involving a digestive system Are motile and grow throughout tissues (no mersitems)

Question:Please please help. I can't find the answer.

Answers:While they do synthesize some of the micromolecules needed in turn for macromolecular synthesis and growth, they get the rest of their nutrition from the host cell. They not just parasites. They're obligate parasites: without a host, they're toast (hey, that rhymed. LOL) That should pretty much make them heterotrophs.