Vitamin amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B (thiamine), vitamin B (riboflavin), vitamin B (niacin), vitamin B (pantothenic acid), vitamin B (pyridoxine), vitamin B (biotin), vitamin B (folic acid or folate), vitamin B (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones). Vitamins have diverse biochemical functions. Some forms of vitamin A function as regulators of cell and tissue
Brasilsat B2 Signaling, located in Rio de Janeiro, as well as automation and installation of security equipment in the Tanguá Control Station. In January 2008, Brasilsat B2 was moved from its former orbital position at 65.0°W to 92.0°W. Brasilsat B2 is now in inclined orbit at 63º W. Of the four Brasilsat satellites, only B3 and B4 are currently transmitting signals. Brasilsat B2 Brasilsat B2 is a Brazilian communications satellite launched on March 28, 1995, by an Ariane rocket model 44L at Kourou in French Guiana. The Boeing Company contracted the acquisition of three satellites from Hughes Electronics Corporation. As part of