Chopping onions unleashes a “chemical defense that onion plants have to protect themselves against insects and microbes,” says UW-Madison horticulture professor Irwin Goldman. We’re just innocent bystanders, it seems.
Goldman explains that one compartment inside onion cells contains an enzyme, called allinase, while another compartment holds the enzyme’s substrate: a suite of sulfur compounds known as [...]

The moment a knife slices through apple—spilling the contents of apple cells along the surface of the cut, and allowing everything to mix—a reaction begins. In particular, an enzyme known as polyphenol oxidase that had been held in check is loosed.
Almost immediately, it begins altering polyphenols, a group of health-promoting chemicals with antioxidant activity that [...]

Enzyme that helps cancer cells move to a new location is found.