1. Ch: 2 The Chemistry of Life 1

2. 2-1 The Nature of Matter Atom – the basic unit of all matter Means “unable to be cut” Made up of a nucleus and electrons Nucleus – center of the atom Protons – positively charged particle Neutron – no charge Electrons – negatively charged particle Element – one type of atom Isotopes – atoms of the same element that have the same number of protons but a different number of neutrons. 2

3. Compound – a combination of 2 or more elements Ionic bond – the transferring of electrons from one atom to another Ion – a positively or negatively charged atom due to chemical bonding. Covalent bond – when electrons are shared between atoms 3 2-1 The Nature of Matter

4. Water is a polar molecule. Polarity – A molecule in which the charges are unevenly distributed. Polar molecules take on a bent shape. Polar molecules are attracted to other polar molecules and form hydrogen bonds between one another. 4 2-2 Properties of Water – the most abundant compound in living things

5. Cohesion – an attraction between molecules of the same substance. Adhesion – an attraction between molecules of different substances. Water has a high specific heat capacity - takes a large amount of heat to raise the temperature. Capillary action – the ability to move upward against gravity. Due to the combined properties of adhesion and cohesion. 5

6. Surface tension – because water is polar and bonds with other water molecules it creates hydrogen bonds that create a small amount of tension on the surface. Mixture – A material composed of 2 or more elements or compounds that are physically mixed together but not chemically. Solution – a mixture of 2 or more substances in which the molecules are evenly distributed 6 2-2 Properties of Water

7. Solute – substances that get dissolved in a solution. Solvent – the substance in which the solute dissolves in; it does the dissolving. Suspension – A mixture of water and non-dissolved materials. Like Italian salad dressing. 7 2-2 Properties of Water

8. 2-3 Carbon Compounds 8 Carbon will: Form four covalent bonds Bond with itself forming straight chains, branched chains, or rings Form single, double and triple bonds.

9. 9 2-3 Carbon Compounds Methane AcetyleneButadieneBenzeneIsooctane Question: How many pairs of electrons do the carbon atoms share in acetylene?

10. Macromolecules – Giant Molecules Polymerization – process of making macromolecules -small compounds are connected to make a large one monomer – small unit that can join to form polymers AKA building blocks polymer – large molecule that results from the joining of monomers 10 2-3 Carbon Compounds

11. Major Polymers and their common names - Carbohydrates – sugar and starches Lipids – fats, oils, cholesterol and waxes Nucleic Acids – DNA and RNA Proteins - Meats, enzyme, muscle 11

12. Carbohydrates - sugars and starches Consist of carbon, hydrogen, and oxygen atoms usually in a ratio of 1: 2: 1 (CHO) Major Functions Main source of energy in living things Also used for structural purposes in plants and some animals (cellulose). Building Block/ Monomer is the simple sugar or monosaccharide 12

13. Same formula (C 6 H 12 0 6 ), different arrangement – also known as Isomers Glucose main sugar burned for energy Fructose – fruit sugar Galactose found in milk Types of monosaccharide's 13

14. Disaccharides = two Monosaccharides  chemical formula (C 12 H 22 O 11 ) Sucrose – table sugar Maltose – malt sugar Lactose – milk sugar Polysaccharides –many monosaccharides Glycogen – glucose storage in animals Starch – plants storage of glucose Cellulose – found in cell wall of plants - strength and rigidity 14

15. Lipids - fats, oils, waxes and steroids long chains of C, H, O atoms --with no set ratio Fatty acid chain and glycerol Major Functions Long term storage Insulation and Cushioning Main component in the cell membrane Chemical Messenger - steroids Waterproofing 15

16. Triglycerides – 3 fatty acid chains bound to a glycerol moleculeTriglycerides 1Glycerol+ 3 Fatty Acids  1Triglyceride 16

17. Saturated – Max # of H-bonds. Solid at room temp. No double bonds Unsaturated – Less than max # of H- bonds. Liquid at room temp Monounsaturated – one double bond Polyunsaturated – more than one double bond 17

18. Proteins Contain - C,H,O,N Affect rate of reactions – enzymes Structural component in muscle, bone and skin Help fight disease – antibodies Serve as cell markers and receptor sites Transport materials into and out of the cell 18

19. Building block/Monomer – amino acid Typical amino acid central carbon amino group –( NH2) carboxyl group – (COOH) R group- varies with amino acid (20 different ones) Proteins 19

20. Types Dipeptide: 2 amino acids Polypeptide: 3 – 100 amino acids Protein: 100 – 1000 amino acids in length All connected by peptide bonds. Proteins 20

21. Nucleic Acids Contain C,H,O,N,P Store and transmit hereditary or genetic information Essential in the manufacture of proteins Building block/monomer - nucleotide Nucleotides 5 carbon sugar phosphate group nitrogenous base Types DNA –deoxyribonucleicacid RNA – ribonucleic acid 21

22. Biochemical Reactions Dehydration Synthesis – anabolism - polymers are formed – releases water monomer + monomer  polymer + water Example: monosaccharide + monosaccharide  disaccharide + water Hydrolysis - catabolism – large molecules (polymers) broken into simpler ones (monomers) – takes in water polymer + water  monomer + monomer Example disaccharide + water  monosaccharide + monosaccharide 22

23. Add H 2 O Separate polymer into: 2 monomers Remove Water Two Monomers Bond= polymer 23

24. 2-4 Chemical Reactions and Enzymes Chemical Reactions – changes one set of chemicals into another set of chemicals Reactants – Chemicals getting changed Products - produced by a chemical reaction Reactants Products CO 2 + H 2 O  H 2 CO 3 Energy in Reactions Bonds broken = energy released Bonds Formed = energy absorbed 24

25. Exergonic Reactions - release energy = spontaneous Endergonic Reactions – absorb energy = need another source of energy Activation Energy – the energy needed to get a reaction started Energy-Absorbing Reaction Energy-Releasing Reaction Products Activation energy Activation energy Reactants Endergonic ReactionExergonic Reaction 25

26. Enzymes – proteins - speeds up chemical reactions in living things Catalyst (enzyme) – something that speeds up the rate of a chemical reaction by lowering the activation energy. Catalase – enzyme that breaks down hydrogen peroxide Enzyme specificity - each enzyme catalyzes only one reaction “like a lock and key” 26

27. Enzyme Action Reactants have to collide with enough energy to break bonds and form new ones. Enzymes provide a site where reactants can be brought together to react. Such a site reduces the energy needed for reaction. The Enzyme-Substrate Complex - Enzymes hold the substrates (reactants) to allow them to react with a lower activation energy. - A substrate binds to an enzyme at its active site 27