Compound – two or more diff. types of atoms that are chemically combined CHEMICAL BASIS OF LIFE Basic Chemistry Chemistry – concerned with atomic composition and structure of substances and the reactions they undergo Matter, Mass, and Weight Matter – anything that occupies space and has mass Mass – amount of matter in an object; kilogram Dissociation § Separation of ions in an ionic compound by polar water molecules Electrolytes – dissociated ions Chemical Rxns § Substances interact either to form or to break chemical bonds Weight – gravitational force acting on an object Reactants – substances that enter into a chemical reaction Elements and Atoms Element – simplest type of matter having unique properties Products – substances that result from the chemical rxn Atom – smallest particle of an element Atomic Structure Neutrons – no electrical charge Anabolism – synthesis rxns that occur in the body Protons – positive charges Catabolism – decomposition rxns that occur in the body Electrons – negative charges Metabolism – anabolic + catabolic rxns in the body Nucleus – formed by protons and neutrons Electron cloud – where electrons are most likely to be found Atomic number – no of protons in each atom Mass number – no. of protons + no. of neutrons Electrons and Chemical Bonding Chemical Bonding – electrons are transferred or shared between atoms Ionic Bond – electrons are transferred Covalent Bond – electrons are shared Polar covalent bond – unequal, asymmetrical sharing of electrons Polar molecules electrical charge – molecules Classification of Chemical Rxns 1. Synthesis – combination of reactants 2. Decomposition – breakdown of larger reactants 3. Exchange – decomposition + synthesis with asymmetrical Nonpolar covalent bond – equal sharing of electrons bet. atoms Nonpolar molecules – molecules with symmetrical electrical charge Hydrogen Bonds § Weak attraction bet the oppositely charged regions of polar molecules Molecules and Compounds Molecule – two or more atoms that are chemically combined Reversible Rxns § Reactants can form products, products can form reactants Energy and Chemical Rxns Energy – capacity to do work Potential Energy – stored energy Kinetic Energy – energy caused by movement Chemical Energy – form of potential energy stored in chemical bonds Rate of Chemical Rxns (RCTC) 1. Reactants 2. Concentration 3. Temperature 4. Catalysts (increases the rate of chem rxn without itself being permanently changed or depleted) Acids and Bases Acid – proton donor Base – proton acceptor The pH Scale § Indicates the H+ concentration of a solution Ø Neutral – equal no. of H+ and OH-; pH of 7.0 Ø Acidic – H+ > OH-; pH less than 7.0 Ø Basic – H+ > OH-; pH greater than 7.0 7.35 – 7.45 – normal pH range of blood Acidosis – blood pH drops beow 7.35 M o r a n o , M . A . Alkalosis – blood pH rises above 7.45 Salts § Forms when an acid reacts with a base Polyunsaturated fats – two or more double covalent bonds; safflower, sunflower, corn, fish oils Trans fats – unsaturated fats tha have been altered by addition of H atoms Buffer § Chemicals that resist changes in pH Phospholipids – phosphorus containing molecues Inorganic Molecules § Do not contain Carbon Hydrophilic – water loving; polar end of molecules are attracted to water Oxygen and Carbon Dioxide Oxygen – involved with the extraction of energy from food molecules Hydrophobic – water fearing; non polar end is repelled by water Carbon Dioxide – by-product of the breakdown of food molecules Water 1. 2. 3. 4. Stabilizing body temperature. Protection; lubricant/cushion. Facilitating chemical reactions. Transporting substances Organic Molecules § Carbon containing Carbohydrates § CHO Monosaccharides – smallest carbohydrates; simple sugars Ø Glucose – blood sugar Ø Fructose – fruit sugar Disaccharides – 2 monosaccharides Ø Sucrose – table sugar Polysaccharides – many monosaccharides Ø Glycogen – animal starch v Plant starch v Cellulose Lipids § Substances that dissolve in non polar solvents § CHO + P + N Fats – important energy-storage molecules; pad and insulate the body Eicosanoids – important chemicals derived form fatty acids; important regulatory molecules Prostaglandins – regulates secretion of hormones, blood clotting, and some reproductive functions Steroids – carbon atoms in four ring-like structures Cholesterol – important steroid bcos steroid molecules are synthesized from it; important component of cell membranes Proteins § CHON + S § Regulate chemical reactions § Serve as structural components § Cause muscle contraction Amino acids – building blocks of proteins; amine group + carboxyl group; 20 basic types: 12 simple org. molecules + 8 obtained in diet Denaturation – change in shape caused by abnormally high temp. or change in pH Enzymes – protein catalysts; lower the activation energy Activation energy – energy needed to start a chem rxn Lock-and-key model – the shapes of an enzyme and those of the reactant allow the enzymes to bind easily to the reactants Nucleic Acids: DNA + RNA Deoxyribonucleic acid (DNA) – genetic material of cells Glycerol & Fatty Acids – building blocks of fats Ribonucleic acid (RNA) – important role in gene expression/protein synthesis Triglycerides – most common type of fat molecules Nucleic acid – large molecules composed of CHONP Saturated Fatty Acid – single covalent bond; beef, pork, whole milk, cheese, butter, eggs, coconut oil, palm oil Nucleotides – basic building clocks of DNA + RNA Unsaturated Fatty Acid – one of more double covalent bonds Mono-unsaturated fats – double covalent bonds bet. carbon; olive and peanut oil Adenosine Triphosphate (ATP) § Important organic molecule § Energy currency of cells § Stores and provides energy M o r a n o , M . 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