Obtaining Carbon Compounds

DECOMPOSERS

When inorganic nutrients enter the food chain they are converted into carbon compounds (carbohydrates and proteins)

These carbon compounds are locked up inside the tissues of living plants and animals

When an organism dies the nutrients in the tissues are released

Decomposition: the process of breaking down dead organisms and waste products

This is carried out by decomposers

  • enables the cycling of nutrients

  • Saprotrophs: release enzymes that break down complex insoluble carbon compounds into soluble ones (releases inorganic nutrients)

    • they absorb some of the nutrients themselves via active transport

AUTOTROPHS AND CARBON COMPOUNDS

Usually the producers in a food chain are autotrophs, while consumers are heterotrophs

Heterotrophs: synthesise organic compounds by taking in and digesting carbon compounds

  • Saprotrophs: feeds on non-living matter by secreting enzymes and absorbing products

  • Consumers: ingest organic matter which is living or recently killed

Autotrophs: organisms that use external energy sources to synthesise carbon compounds from in organic substances

  • Photoautotrophs: make organic compounds using energy derived form the sun

  • Chemoautotrophs: make organic compounds using energy from the oxidation of chemicals

Autotrophs as organisms that use external energy

All organisms need carbon-containing compounds

  • Amino acids - build up proteins

  • Carbohydrate (monosaccharides) - to build up polysaccharides for energy production

  • Vitamins, minerals, fatty acids - cell membranes

Photoautotrophs use sunlight as an energy source

Reaction: photosynthesis to produce chemical energy (amino acids, glucose)

Autotrophs use sulfur, hydrogen, iron sulfides, hydrogen or ammonia as energy sources

Reaction: oxidation to synthesise chemical energy in the form of carbon compounds

HETEROTROPHS

Obtain carbon compounds from other organisms to synthesise the carbon compounds they require

  1. Ingestion

  2. Digestion

  3. Absorption

  4. Assimilation - the process where the digested nutrients are made part of the cell by building up complex macromolecules (anabolism)

  5. Elimination

Consumer

Type of organism: animals

Digestion of food: internally

Sources of food and mechanism of intake: live or recently dead matter is ingested and broken down

Products of digestion: amino acid, monosaccharides, fatty acids

Saprotrophs (decomposers):

Type of organism: mushrooms/fungi, bacteria

Digestion of food: externally

Sources of food and mechanism of intake: dead and decaying matter is digested by externally released enzymes and absorbed

Products of digestion: amino acid, monosaccharides, fatty acids

Living organisms need energy for a range of different cell activities:

  • Synthesise of large molecules like DNA, RNA and proteins

  • Active transport of molecules across membranes

  • Vesicular transport of molecules with cells

  • ATP supplies all the energy