Chemistry of Life PDF

CHEMISTRY OF LIFE  Atom: The basic unit of matter The structure of an atom: Protons, neutrons, electrons  Element pure substance consisting of 1 type of atom (see periodic table of elements pg. R 15 in agenda) Protons = atomic number Neutrons = Atomic mass – protons So,...

CHEMISTRY OF LIFE  Atom: The basic unit of matter The structure of an atom: Protons, neutrons, electrons  Element pure substance consisting of 1 type of atom (see periodic table of elements pg. R 15 in agenda) Protons = atomic number Neutrons = Atomic mass – protons So, Krypton has 36 Protons 48 Neutrons Electrons must equal protons, because all atoms have an overall neutral charge So, Krypton has 36 electrons Changing the atomic number (protons) creates a new element 4 elements make up 96% of living matter: Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N)  Isotopes: atoms of the same element differ in # of neutrons have same # of protons & electrons  Carbon 12 Carbon 12 6 electrons 6 protons 6 neutrons Carbon 13 Carbon 13 6 electrons 6 protons 7 neutrons Carbon 14 Carbon 14 6 electrons 6 protons 8 neutrons This one is radioactive  Radioactive Isotopes: unstable nucleus that breaks down at a constant rate. Remember: Changing the atomic number (protons) creates a new element Radiation can be: dangerous used to age fossils treat cancer kill bacteria in food used as “tracers” Compound: 2 or more elements bonded in a fixed proportion Example: C6H12O6  Ionic Bond electrons are transferred Atom loses an e- = + charge Atom gains an e- = - charge  Figure 2-3 Ionic Bonding Section 2- 1 Sodium atom Chlorine atom Sodium ion Chloride ion (Na) (Cl) (Na+) (Cl-) Transfer of electron Protons Protons Protons Protons +11 +17 +11 +17 Electrons - Electrons - Electrons - Electrons - 11 17 10 18 Charge Charge Charge Charge - 0 0 +1 1  Covalent Bond Electrons are shared  molecule: atoms held by covalent bonds  You must be able to draw & label 2 connected water molecules (see the next slide) H H Covalent + + bonds ------------- H H O- + + Hydrogen bonds: O- (weak bonds between polar molecules Properties of Water 1. Polarity: unequal sharing of e-, creating a slight + and a slight - charge 2. Cohesion: water clings to water creates surface tension (elastic quality) 3. Adhesion: water clings to another polar substance 4. Capillary action: the upward movement of water 5. Mixture: 2 or more elements physically (not chemically) mixed together; life is made of mixtures involving water Types of Mixtures A. Solutions: solute + solvent @ equilibrium – solute: substance that is dissolved – solvent: dissolves the solute B. Suspensions: water & non-dissolved material; ex. Cells in bloodstream 6. Ionizes: breaks & forms bonds H2O H+ + OH- Water hydrogen hydroxide ion ion  Ions: atoms that have acquired a net electric charge by gaining or losing one or more electrons. pH scale: indicates the concentration of hydrogen ions in solution; ranges from 0-14 Acids: below 7 on the pH scale; more H+ than OH- Bases: above 7 on the pH scale; more OH- than H+ Neutral: 7 on the pH scale; OH- = H+  You need to color & label the pH scale into your notebook! Label acids, bases, neutral, weak & strong for both acids & bases  Buffers: weak acids or bases; react with strong ones to prevent sudden changes in pH  Quiz Atom element Compound Radioactive isotope Ionic bond Covalent bond Hydrogen bond Capillary action Adhesion Cohesion Molecule Solute Solvent solution Macromolecules  CH CH O O carbohydrates lipids Macromolecules proteins Nucleic acid CHON CHON P  Memory Tool CHO CHO CHON or CHONS CHONP  Carbohydrates Made of CHO Usually end usually in 1:2:1 in “ose” ratio Ex. sucrose Ex. C6H12O6  The monomer for carbohydrates is monosaccharide The polymer for carbohydrates is polysaccharides Be sure to view this as a slide show, otherwise some of the words on the next slide will be covered up.  3 Types of Carbs Monosaccharides = 1 sugar Ex. Glucose C6H12O6 & Fructose Disaccharides = 2 sugars Ex. Sucrose, maltose, lactose Polysaccharides = many sugars Ex. Cellulose, starch, glycogen  e arid h acc Dis hydrolysis s ri de c cha s a o no M  3 Types of Polysaccharides Cellulose: in plant cell walls, gives support Starch: in plants, stores energy Ex. Potatoes, corn, pasta, bread Glycogen: forms from digested starch, stored in muscle, provides energy  Lipids (fat) Do not dissolve in water, to dissolve Made of CHO, in alcohol & ether Glycerol + 3 fatty acids Ex. Fats, wax, shaped like “E”, cholesterol, steroids, oil, cell =triglycerides membrane Glycerol + 3 Fatty Acids = Triglyceride = monomer saturated unsaturated  Partially hydrogenated fats, or trans fats, extend the shelf life of food. They They make food more pleasing to the mouth. Think of buttery crackers and popcorn, crispy French fries, crunchy fish sticks, creamy frosting and melt-in-your mouth pies and pastries. All these foods owe those qualities to trans fats. Types of Lipids: Sex Cholesterol hormones LDL: bad Plant steroids: ex. HDL: Digitalis, stimulates good the heart Anabolic steroids Saturated fat: Unsaturated solid at room fat: liquid at temp. Synthetic: room temp. created to treat dwarfism, often Found in: Meat, Vegetable milk, butter abused oil, fish  Purpose of Lipids Stores twice the energy of carbs Essential for cell membrane formation  Protein Made of Forms Metabolic CHON Structures: purpose: = amino Organs, acids = enzymes, spider webs, usually end in “Building feathers, “ase” blocks of hair, bone life” or Ex. lactase Monomer Amino acids  Answer the following questions, write the question. 1. Which of these words are enzymes? Lactase, sucrase, maltase, glucose 2. Are sex hormones lipids, carbs or protein? 3. Which is the bad cholesterol LDL’s or HDL’s 4. Which stores more energy, carbs or lipids? 5. What are amino acids? 6. Is your heart, liver & hair made of protein or carbs or lipids? 7. List the 4 macromolecules  Nucleic Acids Made of CHONP Ex. DNA & RNA = nucleotides “Instructions for Consists of: life” sugar, nitrogen base, phosphate  Quiz subjects Quiz is on: Monosaccharide, Disaccharide, Polysaccharide What letters sugars usually end in Cellulose Glycogen CHO, CHO, CHON, CHONP Examples of carbs, lipids, protein, nucleic acid What letters enzymes usually end in Amino acids  Chemical reactions Chemical Reactions 1. Release or absorb energy 2. Break or form bonds 3. Are usually reversible 4. Require activation energy Examples of Chemical Reactions CO2 + H2O H2CO3 Reactants or substrate Products H2CO3 CO2 + H2O Reactants Products or substrate  Activation Energy: energy needed to start a chemical reaction Catalyst Lowers activation energy Speeding up chemical reactions  Activation energy Activation energy Enzymes 1. are biological catalyst 2. are found in cells 3. are made of protein 4. usually end in “ase” 5. are shape specific 6. reusable 7. may be destroyed by: pH & Temperature Draw an enzyme/substrate complex Answer the following questions, do write the question 1. All enzymes have a specific ____ 2. Are enzymes reusable? Yes or no 3. Enzymes live in your ____ 4. What two things can destroy enzymes? 5. Choose the enzyme from this list Sucrose, lactase, starch, glucose 6. What is the product in this reaction? 2H2O2 2H2O + O2