Ubiquinone


The name ubiquinone is a shortened form of ubiquitous quinone a term coined to describe the observation that this substance can be found m all cells The length of its side chain varies among different organisms the most common form m vertebrates has n = 10 and ubiquinones m which n = 6 to 9 are found m yeasts and plants  [c.1013]

The decline in immune function may pardy depend on a deficiency of coenzyme Q, a group of closely related quinone compounds (ubiquinones) that participate in the mitochondrial electron transport chain (49). Concentrations of coenzyme Q (specifically coenzyme Q q) appear to decline with age in several organs, most notably the thymus.  [c.431]

Figure 12.13 Photosynthetic pigments are used hy plants and photosynthetic bacteria to capture photons of light and for electron flow from one side of a membrane to the other side. The diagram shows two such pigments that are present in bacterial reaction centers, bacteriochlorophyll (a) and ubiquinone (b). The light-absorbing parts of the molecules are shown in yellow, attached to hydrocarbon "tails" shown in green. Figure 12.13 Photosynthetic pigments are used hy plants and photosynthetic bacteria to capture photons of light and for electron flow from one side of a membrane to the other side. The diagram shows two such pigments that are present in bacterial reaction centers, bacteriochlorophyll (a) and ubiquinone (b). The light-absorbing parts of the molecules are shown in yellow, attached to hydrocarbon "tails" shown in green.
The ready reversibility of this reaction is essential to the role that quinones play in cellular respiration, the process by which an organism uses molecular- oxygen to convert its food to carbon dioxide, water, and energy. Electrons are not transfened directly from the substrate molecule to oxygen but instead are transfened by way of an electron transport chain involving a succession of oxidation-reduction reactions. A key component of this electron transport chain is the substance known as ubiquinone, or coenzyme Q  [c.1013]

Coenzyme Q (Section 24.14) Naturally occurring group of related quinones involved in the chemistry of cellular respiration. Also known as ubiquinone.  [c.1279]

Coenzyme Q, oxidized form (Q, ubiquinone)  [c.682]

The resultant fermentation broth was centrifuged to harvest the microbial cells, and they were washed with water and centrifuged a second time, whereupon a living cell paste was obtained. (There was obtained an amount of cells equivalent to 54 parts on a dry basis, which contained 920 /Jg of ubiquinone-10 per gram of dry cells.)  [c.1566]

There are also synthetic routes to the ubiquinones as described in U.S. Patents 3,06B,295 3,B96,153 and 4,062,B79.  [c.1566]

The ready reversibility of this reaction is essential to the role that qumones play in cellular respiration the process by which an organism uses molecular oxygen to convert Its food to carbon dioxide water and energy Electrons are not transferred directly from the substrate molecule to oxygen but instead are transferred by way of an electron trans port chain involving a succession of oxidation-reduction reactions A key component of this electron transport chain is the substance known as ubiquinone or coenzyme Q  [c.1013]

Two groups of substituted l,4-ben2oquiaones are associated with photosynthetic and respiratory pathways the plastoquinones, eg, plastoquinone [4299-57-4] (34), and the ubiquinones, eg, ubiquinone [1339-63-5] (35), are involved in these processes. Although they are found in all living tissue and are central to life itself, a vast amount remains to be learned about their biological roles.  [c.407]

Although it is a general consensus that these 13 substances represent the known vitamins, other compounds upon which there is less agreement often enter the vitamin discussion (25). Included in this group are choline, myo-inositol (Bios I), vitamin E (essential fatty acids including linoleic acid, y-linolenic acid, and arachidonic acid), a-Hpoic acid, ubiquinones, plastoquinone, vitamin P (bioflavonoids), vitamin L (i9-aminoben2oic acid), vitamin T (mixture including foHc acid and vitamin B 2)> vitamin U (T.-methioninylmethylsulfonium chloride), orotic acid (vitamin B23), and pyrroloquinoline quinone.  [c.9]

Lipids alongside with proteins are the major components of biomembranes which directly and constantly contact with the molecular oxygen dissolved both in intercellular and intracellular liquid. This creates objective preconditions for the process of oxidation in them that goes through the stage of formation of free lipid radicals. Easily carried out and autocatalytically amplified in these conditions lipid peroxidation can result in infringement of biological membranes shareture and their functions. But it does not occur due to existence and functioning of the whole hierar chy of protective adaptations - natural antioxidants (AO) - tocopherols, ubiquinones (a synonym coenzyme QIO) and vitamins of group K which are inhibitors of free radical activity.  [c.359]

The name ubiquinone is a shortened form of ubiquitous quinone, a term coined to describe the observation that this substance can be found in all cells. The length of its side chain varies mnong different organisms the most common form in vertebrates has n = 10, and ubiquinones in which n = 6 to 9 are found in yeasts and plants.  [c.1013]

Walker, J. E., 1992. The NADH ubiquinone oxidoreducta.se (Complex I) of respiratory chains. Quarterly Reviews of Biophysics 25 253-324.  [c.708]

Porphyrin-based synthetic receptors for ubiquinone and cytochrome C 98YGK745.  [c.248]

The moist cells were suspended in 750 parts of volume of ethanol and extracted by warming at 60°C for 1 hour. A total of 3 extractions were carried out in a similar manner and the extracts were pooled, diluted with water and further extracted three times with 1,000 parts of volume portions of n-hexane. The n-hexane layer was concentrated to dryness under reduced pressure to recover 4.12 parts of a yellow oil. This oily residue was dissolved in 6 parts by volume of benzene and passed through a column (500 parts by volume capacity) packed with Floridil (100 to 200 meshes). Elution was carried out using benzene and the eluate was collected in 10 parts by volume fractions. Each fraction was analyzed by thin-layer chromatography and color reaction and the fractions rich in ubiquinone-10 were pooled and concentrated under reduced pressure. By this procedure was obtained 0.562 part of a yellow oil. This product was dissolved in 5 parts by volume of chloroform, coated onto a thin layer plate of silica gel GF254 (silica gel with calcium sulfate) and developed with benzene. The fractions corresponding to ubiquinone-10 were extracted, whereby 0.054 part of a yellow oil was obtained. This oil was dissolved in 10 parts by volume of ethanol and allowed to cool, whereupon 0.029 part of yellow crystals of ubiquinone-10 were obtained, its melting point 4B°to 50°C.  [c.1566]


See pages that mention the term Ubiquinone : [c.152]    [c.411]    [c.1013]    [c.1279]    [c.1035]    [c.1035]    [c.45]    [c.522]    [c.522]    [c.522]    [c.404]    [c.1013]    [c.253]    [c.253]    [c.680]    [c.1565]   
Carey organic chemistry (0) -- [ c.1013 ]

Introduction to protein structure (1999) -- [ c.236 ]

Organic chemistry (0) -- [ c.1013 ]