At the time of insemination, sperm along with seminal plasma enters in female reproductive tract and the plasma contains fructose for providing the energy to sperm If the fructose follows just EMP pathway (and not further Krebs cycle). Then what's the need of mitochondria. and if it does enters in Citric acid cycle and further performs oxidative phosphorylation, from where does the oxygen comes?
Glycolysis and oxidative respiration are the main sources of ATP production in a sperm which causes oxygen regulating inside the sperm and makes it capable to move itself in the reproductive tract. But, the nutrients required for the survival of sperm are limited INSIDE THE SPERM.
But, as it enters the reproductive tract, the female body gives all the nourishment required for the sperm to survive, resulting in increased lifespan of the sperm (4-5 days).