Carbon source (biology)
A carbon source is a carbon-containing molecule that is used by an organism to synthesise biomass. Such sources may be organic or inorganic. Heterotrophs must use organic molecules as a source of both carbon and energy. In contrast, autotrophs may use inorganic materials as a source for both, such as inorganic chemical energy (chemolithotrophs) or light (photoautotrophs). The carbon cycle, which begins with an inorganic carbon source (such as carbon dioxide) and progresses through the biological carbon fixation process, includes the biological use of carbon as one of its components.[1]
Types of organism by carbon source[edit]
Autotrophs[edit]
An autotroph is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide,[1] generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis).[2] They convert an abiotic source of energy (e.g. light) into energy stored in organic compounds, which can be used by other organisms (e.g. heterotrophs). Autotrophs do not need a living source of carbon or energy and are the producers in a food chain, such as plants on land or algae in water (in contrast to heterotrophs as consumers of autotrophs or other heterotrophs). Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide.
Heterotrophs[edit]
A heterotroph (/ˈhɛtərəˌtroʊf, -ˌtrɒf/;[3][4] from Ancient Greek ἕτερος (héteros) 'other', and τροφή (trophḗ) 'nutrition') is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but not producers.[5][6] Living organisms that are heterotrophic include all animals and fungi, some bacteria and protists,[7] and many parasitic plants. The term heterotroph arose in microbiology in 1946 as part of a classification of microorganisms based on their type of nutrition.[8] The term is now used in many fields, such as ecology, in describing the food chain.
See also[edit]
References[edit]
- ^ Morris, J. et al. (2019). "Biology: How Life Works", 3rd edition, W. H. Freeman. ISBN 978-1319017637
- ^ Chang, Kenneth (12 September 2016). "Visions of Life on Mars in Earth's Depths". The New York Times. Archived from the original on 12 September 2016. Retrieved 12 September 2016.
- ^ "heterotroph". Dictionary.com Unabridged (Online). n.d.
- ^ "heterotroph". Merriam-Webster.com Dictionary.
- ^ "Heterotroph Definition". Biology Dictionary. 28 April 2017. Retrieved 2 December 2023.
- ^ Hogg, Stuart (2013). Essential Microbiology (2nd ed.). Wiley-Blackwell. p. 86. ISBN 978-1-119-97890-9.
- ^ "How Cells Harvest Energy" (PDF). McGraw-Hill Higher Education. Archived from the original (PDF) on 31 July 2012. Retrieved 10 October 2010.
- ^ Lwoff, A.; C.B. van Niel; P.J. Ryan; E.L. Tatum (1946). Nomenclature of nutritional types of microorganisms (PDF). Cold Spring Harbor Symposia on Quantitative Biology. Vol. XI (5th ed.). Cold Spring Harbor, N.Y.: The Biological Laboratory. pp. 302–303. Archived (PDF) from the original on 7 November 2017.