Melting ice cubes. Melting solid salts. Evaporating liquid water. Converting frost to water vapor (melting, boiling, and evaporation, in general, are endothermic processes.
Photosynthesis requires energy to drive the chemical reaction. Photosynthesis is an endothermic reaction. This means it cannot occur without energy (from the Sun). The light required is absorbed by a green pigment called chlorophyll in the leaves.
