Final answer:
During capacitation, enzymes from the female reproductive tract and the sperm's acrosome remove glycoproteins from the plasma membrane, which is crucial for the sperm to penetrate the oocyte's protective layers and fertilize it.
Step-by-step explanation:
During capacitation, the enzymes in the female reproductive tract and the acrosome strip the glycoproteins from the sperm plasma membrane required for penetration.
Capacitation is a vital process where fluids within the female reproductive tract prepare the sperm for fertilization by improving their motility and modifying the sperm membrane. This allows the release of lysosomal enzymes from the acrosome of the sperm to penetrate the oocyte's exterior layers, including the corona radiata and the zona pellucida, which is a thick glycoprotein membrane that encases the oocyte.
Upon contact with the zona pellucida, the acrosomal reaction occurs, enabling the sperm to release its digestive enzymes and clear a path through the glycoprotein matrix, ultimately allowing it to fuse with the oocyte's plasma membrane and release its haploid nucleus for fertilization.