Function of middle piece is to provide energy, as it consists of mitochondria which is known as the power house of the cell. Semen is only one percent sperm, the rest is composed of over $200$ separate proteins, as well as vitamins and minerals including vitamin $C$, calcium, chlorine, citric acid, fructose, lactic acid, magnesium, nitrogen, phosphorus, potassium, sodium, vitamin $B_{12}$ and zinc.
