Chemistry of Cells - Marengo Community High School：马伦戈社区高中化学的细胞.pptx

Chemistry of CellsChapter 2, Section 3ObjectivesDescribe the distinguishing characteristics of carbohydratesDescribe the important biological functions of polysaccharidesExplain what distinguishes lipids from other classes of biological macromoleculesDescribe the unique properties, building blocks and biological roles of fats, phospholipids and steroidsDistinguish proteins from the other classes of macromoleculesObjectives Cont.List the biological functions which proteins performExplain what determines protein conformation and why it is importantDefine denaturation and explain how proteins may be denaturedDescribe the characteristics that distinguish nucleic acids from the other classes of macromoleculesSummarize the functions of nucleic acidsObjectives Cont.Briefly describe the three-dimensional structure of DNAEvaluate the importance of energy to living thingsRelate energy and chemical reactionsDescribe the role of enzymes in chemical reactionsIdentify the effect of enzymes on food moleculesMacroMoleculesMacro = largeMolecules = 2 or more atoms covalently bondedUsually referred to as polymersLike a chainMade from several repeating subunitsThe repeated subunits are called monomersLike links in a chain3 of the 4 macromolecules are polymers of monomersMaking or Breaking PolymersThe chemical mechanisms that cells use to make and break polymers are similar for all classes of macromolecules.Making PolymersMonomers are connected by covalent bonds via a condensation reaction or dehydration reaction.One monomer provides a hydroxyl group and the other provides a hydrogen and together these form water.This process requires energy and is aided by enzymes. Breaking Down PolymersThe covalent bonds connecting monomers in a polymer are disassembled by hydrolysis.In hydrolysis as the covalent bond is broken a hydrogen atom and hydroxyl group from a split water molecule attaches where the covalent bond used to be.Hydrolysis reactions dominate the digestive process, guided by specif