Acids and bases are chemical substances that release ions when dissolved in water. Acids are compounds that release positive hydrogen ions in water. Bases release hydroxide ions, which are compounds made of an oxygen and a hydrogen. Acids and bases are used around the house for cleaning, but the levels of acids and bases in the body are also important. The body needs a neutral pH and controls the amounts of acids and bases through processes involving the kidneys, lungs and blood.
Acids and bases function to balance the pH levels in the body. Acids and bases are found in foods, the environment and in chemicals including pharmaceuticals. The pH levels in the blood are required to stay neutral, which is at a level of 7. When a dieter eats acidic foods, the body uses a buffering system to neutralize the positive ions released from the acids. Conversely, bases are also controlled to keep the body from becoming too alkaline.
pH is used to measure the amount of hydrogen protons in a substance and the strength of an acid. Strong acids are used in laboratories and cleaning solutions. A strong acid releases more ions in water than a weaker acid, giving it a low pH level. A small pH number means more ions are dissolved in the solution. A higher pH number means the solution is more basic, and fewer hydrogen protons are available in the fluid. Because strong acids and bases are dangerous, most household items are diluted. A pH of 2 is a strong acid, and it is the approximate pH level found in the stomach. The stomach acid helps the breakdown of foods in the body for absorption in the intestines.
Acids and bases have different physical properties. One property of acids is a sour taste (although laboratory chemicals shouldn't be tasted). Foods such as citrus fruits have acidic properties. Vinegar is acetic acid, and it is also sour. Acids are also corrosive and change litmus paper to red.
A property of bases is that the chemicals feel slippery. Household bleach is a common base. Bases also turn litmus paper blue.
Changes in pH in the body lead to physical changes. When your body has too much carbon dioxide, the blood becomes too acidic. Breathing is slowed to increase the pH in the blood. Conversely, if pH in the body is too alkaline, you will hyperventilate in an attempt to lower the pH. This acid and base control is an important part of biological homeostasis in humans.
The body also has a buffer system that helps control the level of acids and bases. pH levels are controlled using bicarbonate or HCO3-. The metabolism in the human body produces high amounts of acids. For example, when working out and building muscles, your muscle tissue produces lactic acid; this acid is picked up and neutralized by the bicarbonate ion.