Answer:
iron
Step-by-step explanation:
Cellular respiration may be defined as the group of metabolic processes as well as reactions which occurs in the cells of the organisms that converts the chemical energy from the oxygen molecules or from nutrients into ATP or adenosine triphosphate and then releases the waste products. Thus it breaks the glucose and produces the ATP. Iron is an important element which are used in many important biological processes in the body like the cellular respiration and oxygen transportation.