Thiamin diphosphate energy metabolism

Thiamin has a central role in energy-yielding metabo-hsm, and especially the metabohsm of carbohydrate (Figure 45-9). Thiamin diphosphate is the coenzyme for three multi-enzyme complexes that catalyze oxidative decarboxylation reactions pymvate dehydrogenase in carbohydrate metabolism a-ketoglutarate dehydro-... 

TMP), thiamine diphosphate (TDP also known as thiamine pyrophosphate, TPP), and thiamine triphosphate (TTP). TDP, the best characterized form, in its role as a eoenzyme for molecules involved in carbohydrate metabolism e.g. transketolase and pyruvate dehydrogenase) is important for energy production and numerous metabolic functions (Lonsdale 2006). 

Thiamin has a central role in energy-yielding metabolism, and especially the metabolism of carbohydrates. Thiamin diphosphate (also known as thiamin pyrophosphate see Figure 11.12) is the coenzyme for three multienzyme complexes that catalyse oxidative decarboxylation of the substrate linked to reduction of enzyme-bound lipoamide, and eventually reduction of NADto NADH ... 

In the metabolism of carbohydrates, thiamin diphosphate is needed in the conversion of pyruvic acid and the sub uent formation of acetyl coenzyme A, which in turn enters the Krebs cycle and produces vital energy. This is one of the most complex and important reactions in carbohydrate metabolism. In addition to thiamin diphosphate, it also requires the following cofactors coenzyme A, which contains pantothenic acid, nicotinamide adenine dinucleotide (NAD), which contains niacin magnesium ions and lipoic acid. 

Thiamin or Bj has been recognized historically as the main cause of beriberi. Thiamin exists in free and bound forms (thiamin diphosphate and the protein-phosphate-thiamin complex). The bound forms are split in the gastrointestinal tract. The absorbed thiamin acts as a coenzyme in energy metabolism, mainly in the conversion of glncose to fats. In addition, it has high implications in the functioning of peripheral nerves (nerve impulses), brain, and muscles. Thiamin deficiency causes... 

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