Why is photosynthesis called a complex and multi-step process?

The processes of all organisms – from bacteria to humans – require energy. To obtain this energy, many organisms gain access to stored energy by consuming food. Carnivores eat other animals, and herbivores eat plants. The process of photosynthesis converts light energy into chemical energy, which can be used by organisms for various metabolic processes. Photosynthesis has evolved as a way of storing energy in solar radiation as high-energy electrons in carbohydrate molecules. During photosynthesis, molecules in leaves capture sunlight and activate electrons, which are then stored in the covalent bonds of carbohydrate molecules. This energy within these covalent bonds will be released when they break down during cellular respiration. Therefore, photosynthesis is a complex and multi-step process.