Nitrate assimilation in eukaryotic cells is a process where nitrate is turned into ammonium, which is then used to make amino acids. This process is found in certain bacteria, fungi, algae, and plants, but not in animals. It requires a lot of energy because eight reducing equivalents are used. Cells regulate this process to avoid wasting energy when ammonium is already available. The way cells regulate this process depends on their type and metabolic state. The main goal of this process is to be efficient with resources.