Need a quiet place to do your work? 1. Use MAP time! (except Wed) OR 2. Go to the LIBRARY! New morning hours start Mon, Nov 11 at 6:45 AM (except Wed) Organic Compounds & Inorganic Substances in Living Things ksuweb.kennesaw.edu/~vking2/Chemistry%20of%20Life%20Post.ppt www.wyalusingrams.com/53942041017952357/lib/53942041017952357/UNIT_2_chemistry.ppt faculty.sgc.edu/asafer/BIOL1107/chapt02_lecture.ppt Introduction a) Organic compounds are carbon-based and are the key substances that make up living things. b) Inorganic substances also are important to organisms, but do NOT contain carbon c) Organic (Carbon) Compounds 1. 2. All living things are made MOSTLY of organic compounds! Yes, you’re organic! The 4 Types of Organic (C) Compounds 3. Organic compounds are made of repeating units called monomers 4. Organic compounds FORM by dehydration synthesis (condensation) 5. Organic compounds are BROKEN DOWN by hydrolysis (decomposition) Part 1: Types of Organic (C) Compounds 1) Carbohydrates Main Use: immediate energy – contain C, H, and O – polysaccharide is a long chains of monomers Examples of carbohydrates: sugars & starches a) Monosaccharides: • glucose (main source of energy for cells) • fructose (in fruit) b) Disaccharides • sucrose (table sugar) • lactose (in milk) c) Polysaccharides (starches) • • glycogen starch stored in liver cellulose fibers in plants 2) Lipids (fats; triglycerides) Main Use: long term energy storage – contains C, H, and O – composed of glycerol + long fatty acid chains a) Saturated fats – contain single bonds - solid fats (related to heart disease) e.g. butter, lard, coconut oil, palm oil b) Unsaturated fats – contain double bonds - liquid oils (healthier) e.g. peanut, corn, olive oils c) Steroids – have a four ring structure Examples: cholesterol (LDL, HDL) sex hormones (testosterone, estrogen), cell membrane bile 3) Proteins Main Uses: Structural –muscle protein fibers Enzymes – catalysts to speed up chemical reactions Energy– only if starvation occurs – contains C, H, O, N – monomer = amino acids – polypeptide is a long chain of amino acids linked by peptide bonds Examples of proteins hemoglobin (in red blood cells) digestive enzymes Enzymes speed up chemical reactions! hydrolysis or decomposition (e.g. digestion) dehydration synthesis - assembles larger organic compounds 4) Nucleic Acids Main Use: store and carry genetic information C, H, O, N and P – monomer = nucleotide – Examples of nucleic acids DNA (deoxyribonucleic acid) is double stranded RNA (ribonucleic acid) is single stranded MATCHING Monomer Organic compound 1. nucleotides carbohydrates 2. monosaccharides lipids 3. amino acids proteins 4. glycerol + fatty acid chains nucleic acids Part 2: Inorganic Substances in Living Things (no carbon) I. Water & Organisms about two-thirds (2/3) of the human body is water!!! Water is essential for cell function; it is required in chemical reactions to sustain life Water is the only common substance in nature in all 3 physical states of matter– solid, liquid and gas A) Polarity of Water Water is a polar molecule with positive (+) and negative (-) ends this leads to easy formation of hydrogen (H) bonds between water molecules Water is a polar molecule Oxygen H H H Hydrogen (H) bonds form between water molecules H Oxygen H bond H H bond H H H B) Properties of Water 1. cohesion--water molecules H bond to one another easily and “cling” together cohesion surface tension water strider (or skater) 2. adhesion--water molecules easily form H bonds to other non-water substances e.g. water travels UP through plant stems & tree trunks adhesion capillary action 3. high specific heat! Water has high specific heat and resists changes in temperature e.g. sweat absorbs some of the heat of your body 4. high heat of vaporization * It takes a significant temperature increase for water to evaporate! 5. Water is less dense as a solid! water E X P A N D S when it freezes Therefore, ice FLOATS in water!! and cells die when the cytoplasm (fluid) inside freezes! e.g. frostbite Euphausid shrimp under ice Ice fishing 6. High solubility water molecules surround molecules water is practically a universal solvent • Many substances are dissolved in biological fluids (vitamins, glucose, oxygen, salts, carbon dioxide, wastes) • Detection by blood & urine tests II. Acids & Bases 1. Acids are substances that form hydrogen ions (H+) in water 2. Bases are substances that form hydroxide ions (OH-) in water 3. The pH scale measures the acidity & alkalinity. pH scale _________________________________________ 0 7 14 acids bases pH < 7 pH > 7 neutral pH = 7 III. Oxygen (O2) • • • cells use O2 to breakdown food into ATP energy molecules during cellular aerobic respiration You need to breathe O2 for energy! No O2, no energy, no life! IV. Salts – dissolve easily in water – form ions (electrolytes) for metabolism (chemical reactions for cell activities) e.g. Na+, Mg2+, Ca2+, K+, Cl- Assignment #27: Create a thinking map entitled, “Chemicals in Living Things” Enzymes Enzymes are proteins that function as catalysts for chemical reactions – they speed up the rate of reactions by lowering the activation energy needed for a chemical reaction to happen Lock and Key Model – – Each enzyme has a specific shape (lock) Substrate (key) the – reactant that must fit into active site of enzyme for reaction to occur One enzyme one specific reaction Enzymes are not changed during the reaction; “reusable” Coenzymes – smaller organic molecules that are needed for a proper fit of an enzyme to substrate e.g. vitamins Cofactors – ions needed for proper fit of enzyme/substrate e.g. Minerals Denaturation – the change of a protein’s shape – – Change the shape, change (usually ruin) the function possible causes: high temperatures, wrong pH or salt concentration