Final answer:
Water is essential to life as it is involved in biochemical reactions, serves multiple functions in the human body, and makes up a significant portion of our body composition.
Step-by-step explanation:
Water is essential to life because biochemical reactions take place in water. Water is continuously lost from the body in multiple ways, including in urine and feces, during sweating, and as water vapor in exhaled breath. This constant loss of water makes water an essential nutrient that must be replenished often.
Water is the most critical nutrient for the human body as it serves as a transportation vehicle, a medium for chemical reactions, a lubricant/shock absorber, and a temperature regulator. Without water, life as we know it would not exist.
Water comprises approximately 60-70% of the human body. It is the largest component of cells, blood, and the fluid between cells. Water also helps regulate our internal temperature and cushions, protects, and lubricates joints and many other body structures.