A sperm cell's structure is very specialized. Its flagellum is used for locomotive function, to rapidly swim directly through the egg cell. While the cytoplasm, it contains organelles, such as the Mitochondria, wherein respiration occurs, to release the energy needed for the sperm's journey towards the egg cell. Sperm cells, contain special enzymes known as acrosomes, this special enzymes allows the sperm to break through the cell membrane of the egg.