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.
According to Scientific American, the longest a human is able to stay awake for is 264 hours, which is 11 days. The first time the record was set was by a 17-year-old named Randy Gardner in 1965; however, Discovery Fit & Health reported on a 42-year-old man named Tony Wright who claimed to have broken that record in 2007.