instruction:
In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
question:
Question: Work is done only if a force is exerted in the direction of what? Answer: motion
answer:
Work is done only if a force is exerted in the direction of motion.


question:
Question: Metabolic enzymes catalyze catabolic reactions that break down what? Answer: carbohydrates
answer:
Metabolic enzymes catalyze catabolic reactions that break down carbohydrates.


question:
Question: What nullified the idea that all biological catalysts are proteins? Answer: discovery of ribozymes
answer:

The discovery of ribozymes nullified the idea that all biological catalysts are proteins.