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.
How long can you stay awake? Randy Gardner holds the record for the longest a person has ever voluntarily gone without sleep, staying awake for 264 hours (about 11 days) when he was 17 for a school science fair project in 1965.