Practice question

Capacitation confers functional competence allowing sperm that are morphologically mature but physiologically dormant after leaving epididymis to fertilize egg. Molecular remodeling includes increased membrane fluidity, sodium bicarbonate influx activating cAMP-PKA pathway, enhanced calcium influx via CatSper, and development of hyperactivated motility pattern and ability to undergo acrosome reaction upon zona encounter. Result is acquisition of sperm-egg recognition and fusion capacity. Without capacitation sperm cannot bind zona or trigger activation. Hence process represents physiological unlocking of fertilization potential within female environment, signaling cascade, membrane preparation essential for conception and embryonic development initiation.