Answer:
Hemoglobin is an iron-containing protein present in the blood that functions for transportation of oxygen to different body cells..
Each hemoglobin molecule have tetrahedral structure consist of four heme groups surrounded by a globin group. Heme, is composed of porphyrin (ringlike organic structure) which is attched to an iron atom. There are four iron atoms in each molecule of hemoglobin that binds with four oxygen atoms and globin carry two linked pair of polypeptide chain.
The oxygen reversibly binds with the polypeptide chain and the process called oxygenation.
Carbon can bond up to 4 times so it can be stronger in some cases than other elements.
Http://www.healthline.com/health-slideshow/home-remedies-for-head-lice#1
This may help :)
Cellular respiration uses energy in glucose to make ATP. Aerobic (“oxygen-using”) respiration occurs in three stages: glycolysis, the Krebs cycle, and electron transport. In glycolysis, glucose is split into two molecules of pyruvate. This results in a net gain of two ATP molecules.