the acrosome reaction occurs in sperm as it approaches the egg.
the acrosome reaction occurs in sperm as it approaches the egg.
when does the acrosome reaction occur in sperm?
as it approaches the egg
acrosome reaction









































during fertilization, a sperm must first fuse with the plasma membrane and then penetrate the female egg cell in order to fertilize it. fusing to the egg cell usually causes little problem, whereas penetrating through the egg's hard shell or extracellular matrix can present more of a problem to the sperm. therefore, sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of the sperm as it approaches the egg. the "acrosome" is a cap-like structure over the anterior half of the sperm's head.
acrosome reaction
sperm that did not initiate the acrosome reaction prior to reaching to the zona pellucida are unable to penetrate the zona pellucida. since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action of the tail, not because of the acrosome reaction itself.
acrosome reaction