Photosynthesis is the process in which green plants use sunlight to make their own food. … Photosynthesis requires sunlight, chlorophyll, water, and carbon dioxide gas. Chlorophyll is a substance in all green plants, especially in the leaves. Food made by the plants in photosynthesis is consumed through metabolic pathways to harness the energy to keep the plants living the energy is in a chemical form as a molecule of adenosine tri phosphate or ATP

There is an energy flow through the ecosystem , as plant transfers the energy to herbivorous organisms and so on therefore plants are called producers because they made their own food and every other living organism is called consumer because they need to extract food from other living beings

However, for other living organisms known as heterotrophs chemical energy or ATP which must be produced for to be used in metabolic processes is extracted from the organic matter obtained from the food
The metabolism is the set of chemical reactions which take place within a living being, in particular to enable it to stay alive, to reproduce itself and to respond to stimuli from its environment. the function of catabolism which is a type of metabolism is to provide energy and the elementary constituents that are essential for the metabolism of the cell. the exact nature of these reactions depends on each organism.
Among the catabolic reactions, the release of the energy contained in the digested organic matter is essential for all hetertrophic beings (consumers) survival