Another type of specialized cell that Anabaena have are akinetes. These are another vegetative cell that enlarges and fills with food reserves. These cells have been found to form about midway between two heterocysts proceeds towards the heterocysts. At maturity these cells are found next to the heterocysts, and provide all the necessary food for them. Since the heterocysts cannot photosynthesize, it is very important for these cells to be near. Also, the enzyme nitrogenase, which is what allows the heterocyst to perform nitrogen fixation, is unstable in the presence of oxygen, so akinetes help to keep these two essential components separated.