Which is the best definition of activation energy? the energy required to end a chemical reaction the energy required to bind a substrate to an active site the energy required to form or break the bonds of reactant molecules the energy required to re-form bonds in product molecules

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.