They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis. Nitrogenase is inactivated by oxygen, so the heterocyst must create a microanaerobic environment.
Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body's genetic material. Vitamin B12 works closely with vitamin B9, also called folate or folic acid, to help make red blood cells and to help iron work better in the body.
Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood.It is one of the eight B vitamins.It is normally involved in the metabolism of every cell of the human body, especially affecting DNA synthesis and regulation, but also fatty acid metabolism and amino acid metabolism. Neither fungi, plants, nor animals (including humans) are capable of producing vitamin B 12.ecause intrinsic factor is crucial for the normal absorption of B 12, its lack in pernicious anemia causes a vitamin B12 deficiency. Many other subtler kinds of vitamin B 12 deficiency and their biochemical effects have since been elucidated.