Mature sperm, or spermatozoa, have three different parts: a head, a mid- piece, and a tail. Mature sperm are stored in the epididymis.
Mid-piece - provides energy for the movement of the tail
Head - covered by an acrosome, a cap containing enzymes needed to penetrate the egg
Tail - The sperm's whip-like tail propels the sperm forward with the energy produced by mitochondria in the mid-piece.