Enzymes involved in synthesis

Biosynthesis of Tea Flavonoids. The pathways for the de novo biosynthesis of flavonoids in both soft and woody plants (Pigs. 3 and 4) have been generally elucidated and reviewed in detail (32,51). The regulation and control of these pathways in tea and the nature of the enzymes involved in synthesis in tea have not been studied exhaustively. The key enzymes thought to be involved in the biosynthesis of tea flavonoids are 5-dehydroshikimate reductase (52), phenylalanine ammonia lyase (53), and those associated with the shikimate/arogenate pathway (52). At least 13 enzymes catalyze the formation of plant flavonoids (Table 4). 

Chemical Source Enzyme involved in synthesis Effect on first-order sensory neuron Pharmacological intervention... 

Figure 1. Control of mitochondrial biogenesis by the nuclear genome. Most mitochondrial proteins, including cytochrome c, are nuclear gene products which are subsequently imported into mitochondria. Similarly, most enzymes involved in synthesis of mitochondrial phosphoplipids are encoded in the nuclear genome. Being located in the endoplasmatic reticulum, they synthesize phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), phosphatidylglycerol (PG) and phosphatidylinositol (Ptdins). The phospholipids are transferred to the outer membrane. The imported lipids then move into the inner membrane at contact sites. Mitochondria then diversify phospholipids. They decarboxylate phosphatidylserine to phosphatidylethanolamine (PtdEtN), but the main reaction is the conversion of imported phosphatidylglycerol to cardiolipin (CL). Cardiolipins localize mainly in the outer leaflet of the inner membrane.

Figure 7.17 The pathway of ketone body oxidation hydroxybutyrate to acetyl-CoA. Hydroxybutyrate is converted to acetoacetate catalysed by hydroxybutyrate dehydrogenase acetoacetate is converted to acetoacetyl-CoA catalysed by 3-oxoacid transferase and finally acetoacetyl-CoA is converted to acetyl-CoA catalysed by acetyl-CoA acetyltransferase, which is the same enzyme involved in synthesis of acetoacetyl-CoA.

The answer is D. As this patient ages, a variety of skeletal defects and short stature that are consistent with a lysosomal storage disease (mucolipidosis), either I-cell disease or pseudo-Hurler polydystrophy, are developing. Both diseases arise from a deficiency of an enzyme involved in synthesis of the Man-6-P marker on lysosomal enzymes. Such misaddressed proteins are secreted rather than trafficked to the lysosomes. The degradative function of lysosomes is impaired as a result and the organelles tend to accumulate waste products (hence, the term storage disease ). It is these inclusion bodies or dense structures that would be visible by microscopic examination of the patient s cells in a biopsy specimen. 

Applied Molecular Evolution of Enzymes Involved in Synthesis and Repair of DNA... 

Answer E. For antitubercular activity, isoniazid (INH) must first be metabolically activated via a catalase present in mycobacteria. A decrease in expression of the cat G gene that encodes this enzyme is the mechanism of high-level resistance to INH. Low-level resistance occurs via mutations in the inh A gene that codes for an enzyme involved in synthesis of mycolic acids. Mutations in the gene that codes for DNA-dependent RNA polymerase is an important mechanism of resistance to rifampin and related antibiotics. 

Sandberg M, Ward H K, and Bradford H F. (1985) Effect of corticostnate pathways lesion on the activities of enzymes involved in synthesis and metabolism of ammo acid neurotransmitters in the striatum / Neurochem 44, 42-47... 

Other enzymes involved in synthesis of oligosaccharide precursors are also found as causative genes for CDGS type I. Mutations on phosphomannoisomerase (PMI),... 

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