The puzzle piece that fits inside an enzyme is called

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

Many humans consume both plants and animals. these humans are considered to be which of the following? herbivores carnivores omnivores

In which energy level are valence electrons located?