Question

how do lysosomes help in fertilization of the human sperm with ova

Answer 1

The head of human sperm has a cap like structure called acrosome. Acrosome contains lysosomal enzymes known as hyaluronidase enzyme. This enzyme is helpful in breaking down the zona pellucida layer of secondary oocyte. After that sperm enters into it and this action prevents entry of other sperms. In the mean time, secondary oocyte changes to ovum under such circumstances. Ultimately the sperm nucleus reach near ovum nucleus and fertilize it. Also lysosomal enzymes help to reach the sperm upto ovum by withstanding harsh environment in female reproductive tract.

Answer 2

Lysosomes :-

The lysosomes are being referred as the police force of the cell. Even in a place as small as a cell, our body needs someone to keep things in order. But unlike the police, these lysosomes literally eat things which disturb the natural order of the cell. Lysosomes pick up foreign invaders such as bacteria, food and old organelles and break them into small pieces that can hopefully be used again. If they pick up a really harmful invader, they will eat up it and expel what is left of it out of the cell so that the waste can be removed out of our body. The lysosomes are able to do this because they are filled with enzymes.

Another important function of lysosomes in human beings occurs during the fertilization of the egg by the sperm. The head of the sperm cell contains a package of lysosomal material called the acrosome. The enzymes from acrosome are released when the sperm makes contact with an egg and they effectively bore a hole through the cell membrane of the egg allowing the sperm to enter. The Lysosomal enzymes help in breaking down the zona pellucida of the egg. As the sperm approaches zona pellucida of the egg, which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane of the sperm head, exposing the contents of the acrosome. The contents include surface antigens necessary for binding to the egg's cell membrane, and numerous enzymes which are responsible for breaking through the egg's tough coating and allowing the fertilization.