2 Building Blocks of Matter The basic unit of matter is the atomAtoms are made of subatomic particles: protons (+), electrons (-), and neutronsProtons and neutrons reside in the nucleusElectrons move around in orbitals outside of the nucleusAtoms of the same element but with different neutrons are isotopesCarbon-12, Carbon-13, Radioactive Carbon- 14
3 Building Blocks of Matter Two or more elements can combine to form compounds (H2O)Ionic bonds hold a compound together by a transfer of an electron leading to charged elements (NaCl)Covalent bonds involve sharing of electrons between elements (H2O)
4 Building Blocks of Life Element – Substance that can’t be broken down into simpler chemical substances.Carbon - the element of life as it can combine with other elements and with itself to form long complex structures. It must have 4 bonds.
5 Macromolecules Macromolecules – big molecules Monomers – small subunits (building blocks) of large molecules, ex. Glucose is the monomer of starch, a polymerPolymer- made of many molecules, ex. proteins, nucleic acids
6 Carbohydrates Main source of energy for living organisms (glucose) Organisms store energy as complex carbohydrates called starches
7 Carbohydrates Monosaccharide – single sugar. Polysaccharide – large molecules formed from monosaccharides.
8 LipidsComposed predominately of carbon and hydrogen atoms (limited oxygen)Includes fats, oils, waxes, steroidsComposed of glycerol and fatty acids
10 Nucleic Acids Composed of monomers called nucleotides Composed of 5-C sugar, phosphate group, and a nitrogenous baseJoined together to form nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)Store and transmit hereditary (genetic) information
15 Organic Macromolecules CompoundSubunit(s)ElementsFunctionExamplesCarbohydratesGlucose or sugarC, H, OMain energy sourceStructureglucose, starch, cellulose, glycogenLipids(fats & oils)Glycerol and 3 fatty acidsEnergy storageProtective coveringsPhospholipids, steroidsProteinsAmino acidsC,H,O,N, & usu. SMuscles/bones/structureControl reaction ratesRegulationTransport substancesFight diseaseInsulin, enzymes, hemoglobin, muscle fibersNucleic acidsNucleotidesC, H, O, N, PStore and transmit genetic informationDNA, RNA
16 Chemical ReactionsChemical reactions involve the breaking of bonds in reactants and the formation of new bonds in productsThose entering the reaction are reactantsProducts are produced by the reaction
17 Chemical ReactionsEquations must balance. Atoms are not created or destroyed, just rearranged.Example: 2H2 + O H2OReactants are on the left and enter into the reaction.Products are on the right and result from the reaction.Metabolism – All of the chemical reactions that occur within an organism.
18 Energy in Reactions 2H2 + O2 2H2O Occurs naturally, releasing energy The reverse reaction: 2H2O H2 + O2 requires so much energy it rarely occurs
19 Chemical ReactionsActivation energy – energy needed to get a reaction started.Catalyst – substance that speeds up the rate of a chemical reaction.Enzymes – proteins that speed up chemical reactions because they lower the activation energy. Enzymes provide a site where reactants can be brought together. (This reduces the energy needed for the reaction, called activation energy).Substrate – the reactant(s) the enzymes fit.
22 EnzymesEnzymes can be affected by any variable that affects chemical reactions including temperature and pHEnzyme activity are regulated by cells often by turning them on or off
23 Characteristics of Enzymes Specific (a special shape; use induced fit)ReusableNot consumed (used) in the reactionAffected by factors such as pH and temperature.Enzymes are specific because they are proteins made by folding into a 3-D shape (linked to their function).
24 Properties of Water Although water is neutral, it does have polarity Water molecule is polar because of uneven distribution of electronsThe oxygen end has a slight negative chargeThe hydrogen end has slight positive charge
25 Properties of WaterDue to its polarity, water can hydrogen bond with itself (attract itself)Weaker than ionic bonding (NaCl)Cohesion is attraction of molecules of same substance (beads of water)Adhesion is attraction of molecules of different substances (water and graduated cylinder)
26 Properties of WaterWater is not always pure, it is often found as a mixture (material composed of two or more elements or compounds that are not chemically combined)If the materials are evenly distributed it is called a solutionThe substance that is dissolved is the soluteThe substance that dissolves is the solvent
27 Properties of WaterWhen material does not dissolve a suspension is formedExample: blood cells and waterThe movement of the water keeps the small particles suspended
28 Acids and BasespH – A measure of how acidic or basic a solution is. Scale is 0 to 14. Below 7 is acidic. Above 7 is basic. 7 is neutralAcidic solutions have higher concentration of H+ ions than pure water (pH 7)Basic solutions have a lower concentration of H+ ions than pure waterBuffers – prevent sharp, sudden changes in pH