Chemical reactions convert to . In nonliving systems, the presence of a(n) allows the reaction to proceed very quickly and have a lower . In living systems, this function is carried out by proteins called . activation energy
catalyst
enzymes
products
reactants

a polymer is a chainlike molecule made up of small molecular units. these small molecular units are called monomers. monomers of polymer can be joined together either naturally or synthetically.  

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.

yes

no

blue is scattered more than other colors because it travels as shorter, smaller waves. this is why we see a blue sky most of the time.