<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  How does a catalyst speed up a chemical reaction? Context: Catalysts speed up chemical reactions by lowering the activation energy needed for the reaction to take place. Answer: [/INST]A catalyst lowers the activation energy required for a reaction to occur, thereby speeding up the process.</s>