Structure of Haemoglobin: Haemoglobin is an aggregation of four globular proteins (typically two alpha and two beta subunits), each with an embedded haeme group. Each haeme group allows the binding of an oxygen molecule.
Here's another intriguing case from the Guinness World Records. In 1964, a 17-year-old high school student named Randy Gardner beat the world record for sleep deprivation by staying awake for 264 hours (11 days) without using any stimulants.
TIME reported that the was found dead in his sleep. Because of the time difference between Europe and China, soccer matches didn't begin until the middle of the night, between 1 and 3 a.m. In closely-watched experiments, people have been able to stay awake for eight to 10 days straight, Scientific American reported. They didn't suffer any serious health effects, although they did have severe problems with concentration, perception and the like the longer they were awake.