sentence2_structure: organisms<>use<>catalysis<>to speed up reactions$$$organisms<>use catalysis to speed up<>reactions
sentence1: HETEROGENEOUS CATALYSIS (3) Thermodynamics and kinetics of adsorption and reactions and solid surfaces, heat and mass transfer effects, theory and correlations in catalysis.
sentence2: Instead of heat, organisms use catalysis to speed up reactions.
question: Instead of heat, organisms use what to speed up reactions?