Macromolecules

Chapter 5: The Structure and Function of Large Biological MoleculesEssential Knowledge3.a.1 DNA, and in some cases RNA, is the primary source of heritable information (5.5).4.a.1 The subcomponents of biological molecules and their sequence determine the properties of that molecule (5.1-5.5).4.b.1 Interactions between molecules affect their structure and function (5.4). 4.c.1 Variation in molecular units provides cells with a wider range of functions (5.1-5.5).MacromoleculesLarge molecules formed by joining many subunits together.Macro = giant, largeAlso known as polymers.Ex: Carbs, proteins, lipids, nucleic acidsPolymers and MonomersPolymermany units bonded together to make a larger macromoleculePoly = manyMonomer - A building block of a polymerMono = one

Condensation Synthesis or Dehydration Synthesis The chemical reaction that joins monomers into polymersCovalent bonds are formed by the removal of a water molecule between the monomers.HydrolysisReverse of condensation synthesisHydro - water Lysis - to splitBreaks polymers into monomers by adding water

Four Main Types Of MacromoleculesCarbohydratesLipidsProteinsNucleic acidsCarbohydratesUsed for fuel, building materials, and receptors.Made of C,H,OGeneral formula is CH2OC:H:O ratio is 1:2:1Monomers joined by glycosidic linkage (covalent bond)

Types Of CarbohydratesMonosaccharidesDisaccharidesPolysaccharidesMonosaccharidesMono - singleSaccharide - sugarSimple sugars3 to 7 carbonsCan be in linear or ring formsMonosaccharidesCan be Aldoses or Ketoses depending on the location of the carbonyl group.Aldose end of chainKetose middle of chainNotice: names of end in -ose

ExamplesGlucoseGalactoseRiboseFructose

-ose NamesWord ending is common for many sugar/carbohydratesDisaccharidesSugar formed by joining two monosaccharides through a glycosidic linkageExamples:Maltose = glucose + glucoseLactose = glucose + galactoseSucrose = glucose + fructose

PolysaccharidesMany joined simple sugarsUsed for storage or structurePolymers made of glucose monomers (either a or b glucose) Examples:StarchCelluloseGlycogenChitin

StarchMade of 1-4 linkages of a glucoseLinkage makes the molecule form a helixFuel storage in plants

CelluloseMade of 1-4 linkages of b glucoseLinkage makes the molecule form a straight lineUsed for structure in plant cell walls

CommentMost organisms can digest starch (1- 4 a linkage), but very few can digest cellulose (1- 4 b linkage)Another example of the link between structure and functionGlycogenAnimal starchSimilar to starch, but has more 1-6 linkages or branchesFound in the liver and muscle cells

ChitinUsed by insects, spiders, crustaceans to build exoskeletonsAlso found in cell wallsDiffers from cellulose chitin has nitrogen branch connected to glucose monomer

Monomer: GlucosaminePolymer: ChitinLipids On Your Own Firsthttp://www.wisc-online.com/Objects/ViewObject.aspx?ID=AP13204Visit this website and take notes over the material presented; we will go through the ppt after to catch anything missed!

LipidsDiverse hydrophobic moleculesMade of C,H,ONo general formulaC:O ratio is very high in CLipid monomersMade of two kinds of smaller monomers.1) Fatty AcidsA long carbon chain (12-18 C) with a -COOH (acid) on one end and a -CH3 (fat) at the other2) Glycerol

AcidFatNeutral Fats or TriacylglycerolsThree fatty acids joined to one glycerol.Joined by an ester linkage between the -COOH of the fatty acid and the -OH of the alcohol.Saturated vs. Unsaturated FatsSaturated - no double bonds.Unsaturated - one or more C=C bonds. Can accept more hydrogensDouble bonds cause kinks in the molecules shape

FatsDiffer in which fatty acids are usedUsed for energy storage, cushions for organs, insulationOils vs. FatsOil = liquidFats = solidMost animal fats are saturated FATS (like lard and butter.)SolidsMost plant fats are unsaturated fatswe call these OILS (like olive, veggie oil)LiquidsNutrition and DietDiets high in saturated fats cause heart disease Hydrogenated vegetable oil is a product whose unsaturated fats have been converted to saturated fats by adding HQuestion???Which has more energy, a kg of fat (lipid) or a kg of starch (carb)?Fat!!!!! There are more C-H bonds which provide more energy per mass.PhospholipidsSimilar to fats, but have only two fatty acids.The third -OH of glycerol is joined to a phosphate containing molecule.Phospholipids have a hydrophobic tail, but a hydrophilic head.Self-assembles into micells or bilayers, an important part of cell membranes.

SteroidsLipids with four fused rings.Differ in the functional groups attached to the rings.Examples:cholesterolsex hormones

Other LipidsSoaps and detergentsWaxesCertain pigmentsCosmeticsProteinsThe molecular tools of the cellMade of C,H,O,N, and sometimes SNo general formulaPolypeptide chains of Amino Acids linked by peptide bonds

Uses Of ProteinsStructureEnzymesAntibodiesTransportMovementReceptorsHormones

Protein monomers: 20 Amino AcidsAll have a Carbon with four attachments:-COOH (acid)-NH2 (amine)-H-R (some other side group)Amino acid R groupsThe properties of the R groups determine the properties of the protein.20 different kinds:Nonpolar - 9 AAPolar - 6 AAElectrically ChargedAcidic - 2 AABasic - 3 AA

Polypeptide ChainsFormed by dehydration synthesis between the carboxyl group of one AA and the amino group of the second AA.Produce an backbone of: (N-C-C)X

Levels of Protein StructureOrganizing the polypeptide into its 3-D functional shape.PrimarySecondaryTertiaryQuaternary

PrimarySequence of amino acids in the polypeptide chain.Many different sequences are possible with 20 AAs.

Secondary3-D structure formed by hydrogen bonding between parts of the peptide backbone.Two main structures:a helixpleated sheets

TertiaryBonding between the R groups.Examples:hydrophobic interactionsHydrogen bondingionic bondingDisulfide bridges (covalent bond)

QuaternaryWhen two or more polypeptides unite to form a functional protein.Example: hemoglobin

Is Protein Structure Important?

Denaturing Of A ProteinEvents that cause a protein to lose structure (and function).Example:pH shifts (confuses chemical interactions)high salt concentrations (confuses chemical interactions)heat (usually renders proteins inactive)Denaturing, cont.Ex: white of an egg turns white (denatured protein due to heat)Ex: why extreme temps are so deadly to people/animals

Nucleic AcidsInformational polymersPass genetic info from parent to offspringMade of C,H,O,N and PNo general formulaExamples: DNA and RNA

Nucleic AcidsPolymers of nucleotidesCalled polynucleotidesNucleotides have three parts:nitrogenous basepentose sugarphosphate

Nitrogenous BasesRings of C and NThe N atoms tend to take up H+ (base)-b/c of neg chargeTwo types:Pyrimidines (single ring)-C,T,UPurines (double rings)-A,GPentose Sugar5-C sugarRibose - RNADeoxyribose DNARNA and DNA differ in an OH group on the 3rd carbon

DNADeoxyribonucleic AcidMakes up genesGenetic information source for most lifeFound inside nucleusCopied during cell cycle (Interphase)RNARibonucleic Acid.Structure and protein synthesis.Genetic information for a few viruses only.Found inNucleus and near ribosomes in cytoplasmThree typesMessenger (m)Ribosomal (r)Transfer (t)Contains: UracilMacromoleculeMonomerPolymerCarbohydrateMonosaccharideDisacc, Oligio, PolysaccProteinAmino acidPolypeptide chainNucleic acidNucleotideDNA, RNA (Polynucleotide)LipidsFatty acid, glycerolFats, waxes, oils, steroidsSummaryRecognize how dehydration synthesis can be used to build polymers from monomers.Recognize how hydrolysis can be used to break down polymers into monomers.Identify the elemental composition, general formula, types and uses of carbohydrates.Identify the elemental composition, types and uses of lipids.Identify the elemental composition, levels of structure and uses of proteins.Identify the elemental composition and general uses of nucleic acids.