How do enzymes speed up chemical reactions

High energy produced during the metabolism of reactant to product. Due to the large free energy of activation, the speeds of uncatalyzed biochemical reactions are often exceedingly slow. Enzymes lower this energy of activation so that more molecules have adequate energy to carry into the transition state to speed up the rate of reaction.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

trachea, alveoli, lung capillaries, arteries