The activation energy is shown as a 'hump' in the line ... In the profile for an endothermic reaction, the overall change is positive. You can tell this because the products have more energy ...

and the arrow showing the overall change in energy points downwards. In the reaction for an endothermic reaction, the overall change is positive. You can tell this because the products have more ...

Enzymes lower the activation energy necessary to transform a reactant into a product. On the left is a reaction that is not catalyzed by an enzyme (red), and on the right is one that is (green).