Thiamine (vitamin B1) occurs mainly in phophorylated form as thiamine diphosphate (TDP) or as thiamine pyrophosphate (TPP). It has functions as a co-enzyme as well as independent functions. As a co-enzyme, it is required in the mitochondria (power plants of the cell) for a small number of important metabolic processes in the context of energy metabolism. The biochemical processes that take place there require, in addition to thiamine pyrophosphate (TPP), the niacin-containing co-enzyme (NAD), a riboflavin-containing co-enzyme (FAD), and lipoic acid.The enzyme (metabolic accelerator) transketolase is also dependent on thiamine (vitamin B1). This is important for:
- Pentose-phoshphate cycle – oxidation of glucose-6- to pentose-5-phosphate with the formation of NAPH, which is thereby ready for the reduction of oxidizing substances, especially in erythrocytes (red blood cells).
- ATP – adenosine triphosphate – an important energy store in the cells.
- DNA – desoyribonucleic acids (carrier of genetic information).
- RNA – ribonucleic acids, which transfer the genetic information of the DNA for protein biosynthesis (new formation of proteins).
- NADPH – a niacin-containing co-enzyme.
Thiamine triphosphate (TTP) is detectable in nerve and muscle cells and plays an important role in the transmission of nerve signals and muscle actions.
