What proteins are vital to living things because they speed up chemical reactions by up to a trillion times

The answer is; enzymes

These proteins have active site in which the reactants bind and are catalyzed. Enzymes work by lowering the activation energy of reactants hence speeding the rate of reaction. In most cases, these reactions in the body would not happen spontaneously in the environment, due to the high activation energy required, but do so in the body due to the presence of enzymes.