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.
Under the Brain's Control. At a Glance. Staying awake and alert or sleeping restfully when we choose to depends largely on the function of a few small areas of the brain. When the alerting areas of the brain are most active, they inhibit activity in other areas of the brain responsible for promoting sleep. This inhibition of sleep results in stable wakefulness.