Why are supernova events tied so closely to our existence as organisms and to the existence of out planet?

Supernovae are exploding stars, and happen when stars are at the end of their life. During a supernova, all the elements heavier than IRON are made. This means that all atoms with 27 or more protons are created in the explosion, for example, Nickel, Copper, Zinc, Gold, Silver, Mercury, Lead, just to name a few. Elements like Helium, Oxygen, Carbon, Nitrogen and on up to Iron are made in the inner centers of stars. But, it is only when a star blows up in a supernova explosion that these lighter elements can get out. So, you see that a supernova events are important for distributing all the elements that make up planets and organisims. All the known elements are listed in a Periodic Table of Elements, which you can find here and also here and also here