Eli5 what in water Makes it necessary for humans to need it?
In: Biology
It’s actually nothing in water that we need.
Rather – as you may remember from chemistry class – if you just have two solid chemical powders and you sit them next to each other, nothing will happen. You have to dissolve them in water before they start reacting with each other.
That’s why the body needs water: not to use, like, the oxygen and hydrogen in water itself, but to use it as a solvent for all the biochemical reactions that take place in the body.
So the most basic reason is it makes it much easier for everything to mix together and react. Think of one of those water color paint sets. You get a tray with 5 or 6 different colors in there as dry solids. They don’t interact in anyway. Then you get some water in there and you can mix those colors together to make any color you want. When they are dry if the red paint and blue paint are on opposite sides of a tub then nothing happens but off you fill that tub with water then you end up with purple. It is the same in your body glucose needs to be phosphorylated with phosphate from ATP by hexokinase so that sugar you eat can be broken down to give you energy. Glucose, ATP, and hexokinase are all solids. If our body was dry and not 70%ish water they would each sit in their little piles and never interact. But at the molecular level water is bouncing around bumping into those molicules causing them to move around and bump into each other so that then they are able to interact and cause the chemical reaction of phosphorylating glucose.
It’s not really what’s in water. It’s how much water is in us, for us to function. Without it, the body, which is slowly losing water all the time due to environmental- and activity-based water loss, will slowly cease to function. It’s in your saliva, helps move waste out of your body, helps regulate temperature (via perspiration), etc. Without sufficient hydration, almost nothing in the human body functions correctly.
Every cell in your body contains water.
A lot of stuff your body needs is water soluble. Stuff gets transported from A to B. Into cells, out of cells.
Blood is used to transport oxygen (and other stuff) through your entire body.
But the body isn’t a closed loop: you constantly loose water:
Some stuff you don’t need or could be harmful in larger concentration gets filtered out (->kidneys) and exits the body with your urine.
Too cool itself, the body sweats. It evaporates, which cools you down.
That looses water, which you need to replenish.
Water itself is what we need. We are made of it. We also need oxygen but we get that somewhere else. We like water as it is.
Water is known as a universal solvent. What this means is that more things will dissolve in water than in any other liquid.
So we need water so that the chemistry of life, which involves a lot of different chemicals, can take place inside of our cells. These chemicals dissolve into the water inside the cells and then react with each other.
Latest Answers