biosynthesis


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Related to biosynthesis: Purine biosynthesis

biosynthesis

the formation of complex compounds from simple substances by living organisms

Biosynthesis

The synthesis of more complex molecules from simpler ones in cells by a series of reactions mediated by enzymes. The overall economy and survival of the cell is governed by the interplay between the energy gained from the breakdown of compounds and that supplied to biosynthetic reaction pathways for the synthesis of compounds having a functional role, such as deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and enzymes. Biosynthetic pathways give rise to two distinct classes of metabolite, primary and secondary. Primary metabolites (DNA, RNA, fatty acids, α-amino acids, chlorophyll in green plants, and so forth) are essential to the metabolic functioning of the cells. Secondary metabolites (antibiotics, alkaloids, pheromones, and so forth) aid the functioning and survival of the whole organism more generally. Unlike primary metabolites, secondary metabolites are often unique to individual organisms or classes of organisms. See Enzyme, Metabolism

The selective pressures that drive evolution have ensured a diverse array of secondary metabolite structures. Secondary metabolites can be grouped to some extent by virtue of their origin from key biosynthetic pathways. It is often in the latter stages of these pathways that the structural diversity is introduced. All terpenes, for example, originate from the C5 (five-carbon) intermediate isopentenyl pyrophosphate via mevalonic acid. The mammalian steroids, such as cholesterol, derive from the C30 steroid lanosterol, which is constructed from six C5 units. Alternatively, C10 terpenes (for example, menthol from peppermint leaves) and C15 terpenes (for example, juvenile hormone III from the silk worm) are derived after the condensation of two and three C5 units, respectively, and then with further enzymatic customization in each case. See Cholesterol, Organic evolution, Steroid

Biosynthesis

 

the formation of organic substances from simpler compounds, occurring within living organisms or outside them under the action of biocatalysts—enzymes. Biosynthesis is part of the metabolic process of plants, animals, and microorganisms. Compounds rich in energy serve as the immediate source of energy for biosynthesis, but ultimately (for all organisms except bacteria, which themselves accomplish biosynthesis), that source is the energy of solar radiation accumulated by green plants. Every unicellular organism, as well as every cell of a multicellular organism, synthesizes the substances that constitute it. The type of biosynthesis accomplished in the cell is determined by the hereditary information “coded” in its genetic apparatus. Biosynthesis accomplished outside organisms is used widely as a method (sometimes the only possible one) for commercially obtaining biologically important substances—vitamins, certain hormones, antibiotics, amino acids, proteins, and other compounds.

S. E. SEVERIN

biosynthesis

[‚bī·ō′sin·thə·səs]
(biochemistry)
Production, by synthesis or degradation, of a chemical compound by a living organism.
References in periodicals archive ?
In one experiment, scientists injected fire ant workers with their specific PBAN to see if this process influenced the biosynthesis of the trail pheromone.
Morphine biosynthesis in the Papaver somniferum has been investigated for many years.
Classical work by Bloch, Cornforth and Lynen on mammalian and yeast cells in the 1950s culminated in the elucidation of the mevalonate pathway for the biosynthesis of the universal isoprenoid precursors, isopentenyl diphosphate (IPP) (7) and dimethylallyl diphosphate (DMAPP) (8) via acetyl-CoA (11), 3-hydroxy-3-methylglutaryl-CoA (10) and 5-diphospho-mevalonate (9) (for review, see Qureshi and Porter, 1981; Bach, 1995; Bloch, 1992; Bochar et al.
Until now, only 1 disorder with a genetic defect in the biosynthesis of mucin-type O-glycans has been described: familial tumoral calcinosis (FTC) associated with mutations in the UDPN-acetyl-[alpha]-D-galactosamine:polypeptide-N-acetylgalacto -saminyltransferase 3 gene (GALNT3) [7] (6).
In the absence of a functional NIS molecule, iodide has no access to the thyroid follicular cells, resulting in decreased TH biosynthesis and higher circulating levels of TSH, which in turn stimulates the morphologic and biochemical changes in the thyroid that result in development of goiter (De La Vieja et al.
It is clear that rubber biosynthesis proceeds biochemically in fundamentally the same way in all rubber-producing species, and recent, detailed biochemical studies of rubber biosynthesis in Taraxacum kok-saghz (Russian dandelion) have added another species to our list.
This led the search to previously unrecognized enzymes, which the researchers demonstrated were required in the biosynthesis of various rose-scent chemicals, among them geranyl acetate and germacrene D.
L-Tryptophan (L-TRP) serves as a physiological precursor for the biosynthesis of auxins in plants and in microbes (Frankenberger and Arshad 1995).
Chapter 3 describes the mechanisms underlying the biosynthesis and cell biology of the cellular prion protein by using cell culture systems.
His most novel contribution was to exploit the post-war availability of simple Carbon--14 molecules to study the biosynthesis of many alkaloids.
They maintain that the discovery of cellulose biosynthesis in nine species of cyanobacteria, or blue-green algae, may be the source of the genetic material also used for that process in present-day plants such as trees and cotton.
The objective of this paper is to present the results of biochemical and microscopic analyses of callose biosynthesis by arabidopsis plants in response to mechanical injury and to chemical agents.