What is necessary for an enzyme and substrate binds together?

When water freezes, it . contracts expands

Ascientist discovers a new body between the orbit of neptune and the kuiper belt. the object is round and travels in an orbit around neptune with other space objects. the scientist claims that she has found a new dwarf planet. where is the scientist’s error?

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.