Study Guide for Test on the Chemistry of Life

Chapter 2

Be able to compare and contrast ionic, polar covalent, nonpolarcovalent and hydrogen bonds.

(Be sure to understand that hydrogen bonds form between two different moleculesor parts of a larger molecule rather than being the bond that holds together a molecule.)

Be able to define hydrophilic and hydrophobic. Relate the types of bonds (ionic, polar covalent, and nonpolar covalent)to hydrophobic or hydrophilic properties.

Be able to define the following terms: solvent, solute, cohesive, specific heat.

Know why water is: a good solvent, a cohesive substance and has a high specific heat (resists changes in temperature).

Be able to define acid, base and neutral (affect on H+ and OH- concentration of solution).

Be able to explain what the pH scale is, how pH relates to a substance being acidic or alkaline (basic). Be able to explain that the pH scale is logarithmic (powers of 10). For example, know how much more acidic a pH of 4 is compared to a pH of 7.

Be able to explain how and why increased temperature, increased reactant concentration and increased surface area of a reactant (for example powder vs. solid) affect the rate of a reaction.

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 also knowthat hydrolysis reactions occur to break apart these macromolecules. Be able to explain the basic process in both condensation reactions and hydrolysis reactions.

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 and hydrogen, with less oxygen than carbohydrates.

  • Lipids are nonpolar molecules and therefore hydrophobic (insoluble in water).
  • Lipids typically have 2x more energy (calories) than carbohydrates or proteins.

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 explain give examples of some of the roles of different proteins in living things: structural support, enzymes, transport molecules etc.

Be able to define activation energy, exothermic reaction and endothermic reaction. Be able to explain the energy diagrams of both exothermic and endothermic reactions.

Be able to define catalyst, enzyme, substrate and active site.

  • Know that enzymes lower the activation energy of a reaction. Be able to explain the lock and key model of enzyme activity.
  • Understand that each enzyme catalyzes a specific chemical reaction.
  • 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 and why temperature and pH generally affect the reaction rate of an enzyme-catalyzed reaction.
  • Be able to describe and understand the shape of a graph for temperature vs. rate of reaction for an enzyme-catalyzed reaction.