In the evolution of extremely large stars, they begin as supergiants or supernovas, if the star nucleus is large enough it will continue to contract and form neutron stars, and finally, if the contractions continue, everything around the neutron star and the neutron star itself will be pulled into what is called a a. white dwarf c. giant b. nebula d. black hole

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.