Answer:
Enzyme
Explanation:
Enzymes are the biocatalyst found in cells of living beings. The function of enzymes is to speed up the rate of chemical reactions by lowering down the activation energy needed for a reaction to occur. Enzymes are proteins and are not used up during the reactions.
Example: RuBisCo is the enzyme that catalyzes carboxylation of RuBP during first step of dark reactions of photosynthesis.
