Chemistry of Life Test Review (chapter 7) Chemistry Review: 7.1 and 7.2 Be able to compare and contrast ionic and covalent bonds. Be able to compare and contrast the two types of covalent bonds: polar and nonpolar. Be able to interpret an equation for a chemical reaction: knowing that the reactants are on the left of the arrow, products are on the right, subscripts denote the number of atoms of an element in a molecule, coefficients (in front of molecular formula) denote the number of molecules involved in a chemical reaction. Be able to explain why a chemical reaction must be balanced. Be able to define the following terms: solvent, solute, cohesive, specific heat. Be able to define hydrophilic and hydrophobic. Identify which types of bonds relate to hydrophobic properties and which relate to hydrophilic properties. (Of the following: ionic, polar covalent, and nonpolar covalent) Be able to explain what a hydrogen bond is and which type of molecules may be held together by hydrogen bonds. Be able to explain how the fact that water is a polar molecule and forms hydrogen bonds relates to some of its unique characteristics: good solvent, cohesiveness, high specific heat. Be able to define acid, base and neutral (affect on H+ or OH- concentration of water). Be able to explain what the pH scale is, how pH relates to acidity or alkalinity (basic). Be able to explain that the pH scale is logarithmic and know how this relates to the strength of an acid. For example: how much greater is the H+ concentration of a substance that has a pH of 2 compared to one that has a pH of 5? Be able to explain how increased temperature, increased reactant concentration and increased surface area of a chemical reaction are all factors that increase the rate of chemical reactions. And be able to explain that the increase in reaction rate is due to the increased collision rate between reactants. Chemistry of living things: 7.3 Be able to define organic compound and know the 4 main categories of organic compounds: carbohydrates, proteins, lipids (fats) and nucleic acids (DNA and RNA) Be able to define polymer and explain that many organic compounds are polymers. Be able to explain that condensation reactions occur to build polysaccharides, proteins and certain lipids and describe what occurs in a condensation reaction. Be able to explain that hydrolysis reactions occur to break apart the macromolecules listed above and be able to define what a hydrolysis reaction is. Be able to define carbohydrate including the basic ratio of carbon to hydrogen to oxygen in carbohydrates. Be able to explain what monosaccharides, dissacharides and polysaccharides are. Know the function of the following polysaccharides: Starch (energy storage in plants), glycogen (energy storage in animals), and cellulose (structural component of plant cell walls). Be able to explain that lipids have a high proportion of carbon to hydrogen bonds, with less oxygen than carbohydrates. Understand that carbon-hydrogen bonds are nonpolar, and that therefore lipids are not attracted to water (insoluble). Be able to explain the difference between saturated fatty acids and unsaturated fatty acids. Be able to explain that proteins are made of chains of amino acids and that there are 20 types of amino acids in proteins. Be able to outline the basic structure of an amino acid. Be able to explain give examples of some of the roles of different proteins in living things (structure support such as keratin, transport proteins such as hemoglobin, enzymes which catalyze chemical reactions such as amylase). Be able to define catalyst, enzyme, substrate and active site. Be able to explain the lock and key model of enzyme activity. Know that since enzymes are catalysts, they are not changed in a reaction, and can catalyze the same reaction repeatedly. Be able to explain what happens when an enzyme is denatured and how it affects enzyme function. Be able to explain how temperature and pH generally affect the reaction rate of an enzyme catalyzed reaction.