Which of the following best explains how enzymes speed up a chemical reaction?
enzymes remove heat from a chemical reaction.
enzymes add heat to a chemical reaction.
enzymes lower the activation energy of a chemical reaction.
enzymes are not changed as a result of a chemical reaction,

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one