The composition of a chlorophyll molecule consists of a porphyrin ring linked to a central atom. This structural arrangement closely resembles the heme group present in hemoglobin, with the distinction being that heme’s central atom is iron, whereas chlorophyll’s is magnesium.
Chlorophyll and heme are similar because they are both derived from a common ancestor molecule called tetrapyrrole
Tetrapyrroles are organic compounds that have four pyrrole rings connected by methine bridges. The central atom of a tetrapyrrole can be either magnesium, iron, or cobalt, depending on the biological function of the molecule.
Chlorophyll is responsible for the green color of plants and algae, and it plays a vital role in photosynthesis, the process of converting light energy into chemical energy.
Heme is responsible for the red color of blood and muscle, and it is a component of hemoglobin, the protein that transports oxygen in the blood.
