What is capacitation in fertilization

Answer 1

Capacitation is a series of biochemical and physiological changes that sperm cells undergo in the female reproductive tract, which enable them to fertilize an egg. It is a crucial step in the process of fertilization.

During capacitation, the male sperm cells are exposed to the environment of the female reproductive tract, which includes the presence of specific molecules and factors that initiate changes in the sperm's membrane and cytoplasm.

Some of the changes that occur during capacitation include:

1. Hyperactivation: The sperm cells undergo a hyperactive motility pattern, which allows them to move more rapidly and with greater force. This helps the sperm to navigate through the female reproductive tract and reach the site of fertilization.

2. Acrosome reaction: The acrosome, a membrane-bound organelle located at the tip of the sperm cell, undergoes a series of changes. This leads to the release of enzymes that can break down the outer layer of the egg, known as the zona pellucida. The acrosome reaction is essential for the sperm to penetrate and fertilize the egg.

3. Changes in the sperm membrane: Capacitation also involves the removal of certain molecules from the sperm cell membrane, which make it less rigid. This allows the sperm to fuse with the egg's membrane during fertilization.

Overall, capacitation prepares the sperm cells for successful fertilization by allowing them to gain the ability to move more effectively and to undergo the necessary changes to interact with and penetrate the egg.