2 Inorganic Compounds Usually small Lack carbon and/or hydrogen Many contain ionic bondsExamples:Water, oxygen, carbon dioxide, many acids, bases and salts
3 Water The most abundant inorganic substance in the human organism Makes up about 60% of body weightMakes up most of the volume of cells and body fluids
4 Properties of Water Excellent solvent and suspending medium…huh? It dissolves a lot of different thingsSolvent – a liquid or gas in which some other gas is suspendedSolute – the material that is suspended in a solventSolution – combination of a solvent and soluteWater caries nutrients, oxygen, and wastes as well as suspends large organic molecules allowing for essential chemical reations to take place.
5 Water can participate in chemical reactions In decomposition water helps break down large molecules. (hydrolysis)Helps in the synthesis of hormones, enzymes, proteins, lipids and carbohydrates
6 Water absorbs and releases heat very slowly Water requires a large input of energy to increase its temperature and a large release of energy to decrease its temperatureThe large amount of water in the body helps to maintain a constant temperature
7 Water requires a large amount of heat to change from a liquid to a gas When you sweat it takes a lot of energy to evaporate.
8 Water serves as a lubricant As a major part of mucus, saliva and other body fluids, water allows internal organs to slide over each other and lubricates joints where bones, ligaments and tendons rub against each other
9 Acids, Bases and Salts Combination of Ions Dissociation/Ionization – when an ionic substance dissolves in water and breaks apart into the ions that formed itAcids dissociate into H+ ionsBases dissociate into OH- ionsSalts form ions that are not H+ or OH-
10 Acids and Salts react with each other to form salts: HCl + KOH KCl + H2O
11 Acid/Base BalanceThe more H+ in a solution the more acidic something ispH is the measure of how acid something is
12 pH ScaleRuns from 0 – 14Based on the amount of H+ dissolved in solution0 = lots of H+ therefore acidic14 = lots of OH- therefore basic (alkaline)7 means the amount of H+ = OH- (neutral)A change of 1 on the pH scale means a 10x change in concentration
13 Body’s pHThe pH range of blood is (you need to know these exact numbers!)The body maintains pH through the use of buffer systems
14 Buffer SystemsConsist of a weak acid and a weak base that function to prevent drastic changes in the pH of body fluid by rapidly changing strong acids and bases into weak acids and bases
15 Negative Feedback and pH balance Decreased blood pH detected by chemoreceptors in the body control center in the brain sends nerve impulses to the respiratory system diaphragm contracts more forcefully to get rid of more CO2 increase in pH