Professor. Glycolysis Manandhar and Beriberi One of the important cofactors required for the activity of the pyruvate dehydrogenase complex is thiamine pyrophosphate (TPP). TPP is derived from the vitamin thiamine, also called vitamin B 1. The function of TPP in the pyruvate dehydrogenase complex is to destabilize the bond between the carbonyl and carboxyl groups of pyruvate. A deficiency of thiamine causes the disease called beriberi. Oral manifestations of thiamine deficiency include an "old rose" colored tongue, some depapillation at the periphery of the tongue, and a deeper than expected red color of the oral mucosa. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Glycolysis and TCA are responsible for the production of ATP in the body. The Krebs cycle is an important pathway that involves the function of 8 enzymes essential for energy production. This pathway is also an important source of biosynthetics that are used in glucogenesis, the production of glucose. This cycle occurs in the cell's mitochondrial matrix and oxidizes acetyl CoA to gain energy and produce CO2. NADH,FADH,NAD+ and FAD+ are other coenzymes used and essential in this pathway. The Krebs cycle is controlled to adequately meet the needs of the cell and other organisms. Some Krebs cycle enzymes require non-protein cofactors for activity such as thiamine and vitamin B1. Insufficient amounts of this vitamin in the diet lead to a decrease in the activity of pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase and to a decrease in the ability of the Krebs cycle to meet the metabolic demands that cause beriberi disease. The nervous system relies on glucose as its sole fuel. However, in most other tissues it is possible to use fat as a fuel source for the citric acid cycle. The product of aerobic glycolysis, pyruvate, can enter the citric acid cycle only through the pyruvate dehydrogenase complex. In beriberi, the levels of pyruvate and α-ketoglutarate in the blood are higher than normal. The increase in the level of pyruvate in the blood is especially pronounced after ingestion of glucose. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a Custom Assay A related finding is that the activities of the pyruvate and α-ketoglutarate dehydrogenase complexes in vivo are abnormally low. Low red blood cell transketolase activity in beriberi is a reliable and easily measurable diagnostic indicator of the disease.