Chapter 2 Basic Chemistry

Why are We Learning About Chemistry in A&P???? The entire body is composed of Chemicals Those chemicals are continuously interacting in the body at a fast pace Understanding the basics of chemistry will help you properly understand body functions.

Matter & Energy Matter – The “stuff” of the universe. Matter is anything that has weight. Solids Liquids Gaseous Energy – In contrast to Matter it is anything that does not take up space. It is measured by its effects on matter. “ability to do work” Kinetic energy – energy actually doing work (moving objects) Potential energy – energy that is inactive or stored

ATP ATP – Adenosine triphosphate – High energy chemical, the chemical energy of foods is trapped in the bonds of this chemical Provides a form of energy usable by all body cells Body could not function without ATP Glucose could not be broken down Cells could not maintain their boundaries Life would end

Forms of Energy Chemical – Stored in chemical substances. When broken, stored energy is released. body runs on chemical energy Electrical – movement of charged particles Electrical current is generated when charged particles called ions move across cell membranes Mechanical – directly involved in moving matter. Movement of legs to walk or ride a bike Radiant – travels in waves, X-rays, radio, ultraviolet

Composition of Matter Elements & Atoms Elements - unique substances that cannot be broken down into simpler substances by ordinary chemical methods 112 known elements (113-116 alleged) 92 produced naturally 20 artificial

4 Main Elements in the Body Carbon - The primary elemental component of all organic molecules, including carbohydrates, lipids, proteins, and nucleic acids 18.5% of body mass Oxygen – A major component of both organic and inorganic molecules; as a gas, essential to the oxidation of glucose and other food fuels, during which cellular energy (ATP) is produced 65.0 % of body mass Hydrogen – A component of most organic molecules; in ionic form, influences the pH of body fluids 9.5% of body mass Nitrogen – A component of proteins and nucleic acids (genetic material) 3.2% of body mass The 4 Make up 96% of our body weight

9 Lesser Elements in the Body Calcium – Found as salt in bones and teeth; required for muscle contraction, neural transmission and blood clotting 1.5% of body mass Phosphorus – Present as a salt in combination with calcium, in bones and teeth; also present in nucleic acids and proteins, forms part of the high-energy compound ATP 1.0% of body mass Potassium – Major intracellular cation: necessary for conduction of nerve impulses and for muscle contraction 0.4 of body mass Sulfur – A component of proteins 0.3% of body mass

Cont. Sodium – Major extracellular cation; water balance, conduction of nerve impulses and muscle contraction 0.2% of body mass Chlorine – major extracellular anion Magnesium – present in bone, important cofactor for enzyme activity in a number of reactions 0.1% of body mass Iodine – Needed to make functional thyroid hormones Iron – component of functional hemoglobin molecules and some enzymes (RBCs)

Trace Elements Chromium Cobalt Copper Fluorine Manganese Molybdenum Selenium Silicon Tin Vanadium Zinc

Element Symbols You Need to Know Oxygen O Carbon C Hydrogen H Nitrogen N Calcium Ca Phosphorus P Potassium K Sulfur S Sodium Na Chlorine CL Magnesium Mg Iodine I Iron Fe

Atoms The building block of an element, or the smallest particle that still retains its special properties Three subatomic particles Protons – have + charge Neutrons – neutral (no charge) Electrons – have – charge All atoms are electrically neutral (same # of protons and electrons

Molecules & Compounds Molecule – 2 or more atoms combine chemically. If they are both the same then a molecule of that element is produced Ex. H + H = H2 Compound – two or more different atoms bind together Ex. 4H + C = CH4 (methane)

Biochemistry The Chemical Composition of Living Matter All chemicals in the body are either inorganic or organic 1. Inorganic Compounds a. Water * has high heat capacity * 2/3rds of body weight * universal solvent * reactant * cushion – protects b. Salts * ionic compounds that easily separate into ions * vital to body function (nerve impulses & hgb) * considered electrolytes * ionize & dissociate in h2o, conducting electrical current

Acids Also an electrolyte Sour taste Can dissolve metals Can release hydrogen Bases Another electrolyte Bitter taste

pH Acid-Base Concentrations – relative concentration of hydrogen ions in various body fluids is measured in concentration units called pH. Ranges from 0 – 14 pH of 7 is neutral pH < 7 is acidic pH > 7 is basic or alkaline

pH in Blood Normal human blood pH 7.35 – 7.45 When our pH is altered the body will fail and death can occur.

2. Organic Compounds Carbohydrates Monosaccharide Disaccharides Sugars and starches Monosaccharide Sugar / “simple sugar” GLUCOSE Disaccharides Double sugars Sucrose and lactose Polysaccharides Many sugars Storage Starch and glycogen

Lipids Triglycerides Phospholipids Steroids Proteins Enzymes From fat-marbled meat, egg yolks, milk & oil Triglycerides, phospholipids and steroids Triglycerides Neutral fats Fatty acids and glycerol Phospholipids 2 Fatty acid chains Steroids Fat soluble cholesterol Proteins 50% of organic matter in the body Various functions Construction & cell function amino acids are the building blocks of proteins Fibrous and Globular Proteins Enzymes Functional proteins that act as biological catalysts to increase the rate of a chemical reaction.

Adenosine Triphosphate (ATP) Nucleic Acids Make up the genes or blueprint of life RNA & DNA Adenosine Triphosphate (ATP) All important Provides a form of chemical energy that is usable by all body cells