Editing Blood And Buffers (section)

===Full Explanation===
''Buffer Solutions'' are able to resist changes in the pH, or acidity, which keeps the solution from becoming too acidic or basic. Our blood has a very narrow pH range that it needs to stay in, between a pH of 6.8 and 7.4, and to do so it needs to be able to buffer against any extra acid or base. If the blood becomes too acidic or basic, it will affect the bodies homeostasis, and can lead to illness or disease. The cells in our body get energy from simple sugars, with most of them using a reaction similar to this:

;C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> + 6 O<sub>2</sub> → 6 CO<sub>2</sub> + 6 H<sub>2</sub>O + ~38 ATP

The extra CO<sub>2</sub> needs to be filtered out of our blood, and our bodies do that by using what is called the ''Carbonic Acid and Bicarbonate Buffer System''. The CO<sub>2</sub> is taken into the bloodstream, and some of it bonds with water to make carbonic acid. Carbonic acid is a weak acid, which means that most of it will dissociate into a bicarbonate and a free hydrogen, and some of it won't. Bicarbonate is the conjugate base to carbonic acid. This means that the amount of bicarbonate in the solution can change depending on how much carbonic acid is in the solution. The balance between the bicarbonate and carbonic acid is important for the pH of the blood, and works like this:

{| class="wikitable" style="color:black; background-color:#ddd; text-align: center; margin-right: auto"
|+ Carbonic Acid and Bicarbonate Buffer System
|Carbon Dioxide and Water
|
|Carbonic Acid
|
|Bicarbonate and Hydrogen
|-
|CO<sub>2 aq</sub> + H<sub>2</sub>O<sub> l</sub>
|'''⇋'''
|H<sub>2</sub>CO<sub>3 aq</sub>
|'''⇋'''
|HCO<sub>3</sub><sup>-</sup><sub>aq</sub> + H<sup>+</sup><sub>aq</sub>
|}

The red blood cells can move the extra CO<sub>2</sub> between the acid state, the base state and as dissolved CO<sub>2</sub> state, which keeps the system balanced and the pH neutral. This also allows the blood to keep the CO<sub>2</sub> in check until it can be breathed out by the lungs, or until it can be filtered out by the kidneys as bicarbonate or carbonic acid. When a buffer system isn't already in place against the changes, then the extra CO<sub>2</sub> can make the solution too acidic, as you saw with the dry ice in water. Likewise, if there isn't a way to take care of the extra bicarbonate, then the solution can become too basic, as you saw with the baking soda in water.