Chemistry of Life Karen Malt, MSN, RN Part 2 Chemistry of Life Karen Malt, MSN, RN

Chemistry of Life Inorganic Chemistry In living organisms there are two kinds of compounds; Organic- Composed of molecules that contain C-C covalent bonds, C-H covalent bonds, or both. These compounds are generally larger and more complex Inorganic- Compounds whose molecules DO NOT contain C-C or C-H bonds. NOTE: The human body has both types of these compounds and both are important to the chemistry balance of the body.

Chemistry of Life Water; Inorganic compound, necessary for maintaining life. Water is the most abundant compound in the human body. Water is found in and around every cell. Inside the body, water has a slightly “glue-like” property, which helps keep the tissues of the body together. Solvent; A substance in which other substances are dissolved; for example, in saltwater the water is the “solvent” for the salt. Solute; A substance that dissolves into another substance; for example, in saltwater the salt is the solute dissolved in water. Aqueous Solution; when water is the solvent for a mixture. Example: salt (NaCl), and other molecules forms the internal body fluids.

Chemistry of Life Water Chemistry Dehydration Synthesis; A common type of chemical reaction in the human body. Large molecules are formed by removing water from smaller molecules and joining them together. Dehydration of a Cell = loss of water from the cell Dehydration of the body = loss of fluid from the whole body

Chemistry of Life Hydrolysis- this reaction also involves water; the reverse of dehydration synthesis. Water (hydro) disrupts the bonds in large molecules, causing them to be broken down into smaller molecules. NOTE: Water is obviously a very important substance in the body.

Chemistry of Life Chemical Reactions ALWAYS involve energy transfers. Energy is required to build the molecules. Some of that energy is called “stored energy,” which can be released later. Example: ATP; adenosine triphosphate; breaks apart in muscles when contraction of the muscle takes place.

Chemistry of Life Example: K+ + Cl− KCl Example: H2CO3 H+ + HCO3 − Chemical equations represent Chemical reactions In a chemical equation the “reactants” are separated from the product by an arrow. Example: K+ + Cl− KCl Single arrow means the reaction occurs in only one direction, double arrow reaction occurs in both directions. Example: H2CO3 H+ + HCO3 −

Chemistry of Life Acids, Bases, and Salts Although water is integral to the chemistry of life, many other compounds are very important also. Acids and Bases are two compounds, which profoundly affect chemical reactions in the body.

Chemistry of Life Acid; any substance when dissolved in water contributes to an excess of H+ ions (low ph). Application: In the blood, (CO2) Carbon Dioxide forms carbonic acid when it dissolves in water. Some of the carbonic acid dissociates to form H+ ions and HCO3 − (bicarbonate), thus producing an excess of H+ ions in the blood. This creates high CO2 levels making the blood more acidic.

Chemistry of Life Bases; A chemical that when dissolved in water, reduces the concentration of H+ ions in the whole solution. Example: NaOH (Sodium Hydroxide) is a base that forms OH− ions, but no H+ ions. To sum this up, acids are compounds that produce an excess of H+ ions , and bases are compounds that produce an excess of OH− ions (or a decrease in H+).

Chemistry of Life ph ; an expression of relative H+ concentration (acidity): ph value higher than 7 is basic ph value less than 7 is acid ph value equal to 7 is neutral

Chemistry of Life ph balance is carefully regulated by three body systems: Blood Chemicals Lungs Kidneys

Chemistry of Life ph of Body Fluids affects body chemistry so greatly that normal body function can be maintained only within a narrow range of ph. Acidosis- low blood ph Alkalosis- high blood ph Both are very dangerous, but due to homeostasis are well controlled by a well functioning body.

Chemistry of Life Maintaining Homeostasis 1. The body can remove excess H+ ions by excreting them in the urine. 2. Another way of removing acid is by increasing the loss of CO2 by the respiratory system (lungs). 3. Buffers; chemicals in the blood that maintain ph. Buffers maintain ph balance by preventing sudden changes in the H+ ion concentration.

Chemistry of Life

Chemistry of Life Salts; formed when a strong acid and a strong base mix. Example: HCL+ NaOH H+ + Cl− + Na+ + OH− H2O + NACL

Chemistry of Life References Patton, K., Thidodeau, G. (2016). Structure and function of the body (15th ed.). St. Louis, Missouri: Elsevier