Final answer:
The binding of egg sperm peripherical complex (SPC) to the sperm receptors affects the pH during fertilization through the fast block and slow block mechanisms.
Step-by-step explanation:
The binding of egg sperm peripherical complex (SPC) to the sperm receptors affects the pH through various mechanisms during fertilization.
One mechanism is the fast block, which involves a near instantaneous change in sodium ion permeability upon binding of the first sperm, depolarizing the oocyte plasma membrane and preventing the fusion of additional sperm cells. This change in sodium ion permeability affects the pH by altering the balance of ions in the oocyte plasma membrane.
Another mechanism is the slow block, which occurs following an influx of calcium ions triggered by sperm penetration. In this process, cortical granules release zonal inhibiting proteins and mucopolysaccharides into the space between the plasma membrane and the zona pellucida. The release of zonal inhibiting proteins destroys the oocyte's sperm receptors, thus preventing any more sperm from binding. The release of mucopolysaccharides forms an impenetrable barrier that affects the pH by isolating the nascent zygote from its environment.