Chapter 4Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9EnantiomersSlide 11Slide 12Slide 13ATP: An Important Source of Energy for Cellular ProcessesSlide 15You should now be able to:Slide 17PowerPoint Lectures for Biology, Seventh EditionNeil Campbell and Jane ReeceChapter 4Chapter 4Carbon and the Molecular Diversity of LifeFig. 4-2Water vaporH2NH3“Atmosphere”ElectrodeCondenserColdwaterCooled watercontainingorganicmoleculesSample forchemical analysisH2O“sea”EXPERIMENTCH4•Stanley Miller Experiment (1953)•Simulated the process by which organic compounds may have been produced from inorganic precursors during earth’s early formationNameMolecular FormulaStructural FormulaBall-and-StickModelSpace-FillingModel(a) Methane(b) Ethane(c) Ethene (ethylene)Fig. 4-3The Bonding Versatility of Carbon–Allows it to form many diverse molecules, including carbon skeletons (or “backbone”)•The electron configuration of carbon–Gives it covalent compatibility with many different elementsHydrogen(valence = 1)Oxygen(valence = 2)Nitrogen(valence = 3)Carbon(valence = 4)HONCFig. 4-4•Carbon atoms can partner with atoms other than hydrogen; for example:–Carbon dioxide: CO2–Urea: CO(NH2)2O = C = OCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsHHHHHHHHHHHH H HHHHHHHHHHHHHHHHHH HHHH HH H HHH HH HHHHHHHHCCC C CC C C C C C CCCCCCCCCCCCCCCCCCCCCHHHHHHH(a) Length(b) Branching(c) Double bonds(d) RingsEthanePropaneButane2-methylpropane(commonly called isobutane)1-Butene 2-ButeneCyclohexaneBenzeneH HH HHFigure 4.5 A-D•Hydrocarbons Tails in a Fat Molecule–Makes fats hydrophobic(a) A fat molecule(b) Mammalian adipose cells100 µmFat droplets (stained red)Figure 4.6 A, BFig. 4-7Pentane(a) Structural isomers(b) Geometric isomers2-methyl butanecis isomer: The two Xs areon the same side.trans isomer: The two Xs areon opposite sides.(c) EnantiomersL isomerD isomerFig. 4-8DrugIbuprofenAlbuterolConditionPain;inflammationAsthmaEffectiveEnantiomerS-IbuprofenR-AlbuterolR-IbuprofenS-AlbuterolIneffectiveEnantiomerEnantiomersL-Dopa(effective against Parkinson’s disease)D-Dopa(biologically inactive)EnantiomersFig. 4-9EstradiolTestosteroneFig. 4-10aHydroxylCHEMICALGROUPSTRUCTURENAME OF COMPOUNDEXAMPLEFUNCTIONALPROPERTIESCarbonylCarboxyl(may be written HO—)In a hydroxyl group (—OH), ahydrogen atom is bonded to anoxygen atom, which in turn isbonded to the carbon skeleton ofthe organic molecule. (Do notconfuse this functional groupwith the hydroxide ion, OH–.)When an oxygen atom isdouble-bonded to a carbonatom that is also bonded toan —OH group, the entireassembly of atoms is calleda carboxyl group (—COOH).Carboxylic acids, or organicacidsKetones if the carbonyl group iswithin a carbon skeletonAldehydes if the carbonyl groupis at the end of the carbonskeletonAlcohols (their specific namesusually end in -ol)Ethanol, the alcohol present inalcoholic beveragesAcetone, the simplest ketoneAcetic acid, which gives vinegarits sour tastePropanal, an aldehydeHas acidic propertiesbecause the covalent bondbetween oxygen and hydrogenis so polar; for example,Found in cells in the ionizedform with a charge of 1– andcalled a carboxylate ion (here,specifically, the acetate ion).Acetic acidAcetate ionA ketone and an aldehyde maybe structural isomers withdifferent properties, as is thecase for acetone and propanal.These two groups are alsofound in sugars, giving rise totwo major groups of sugars:aldoses (containing analdehyde) and ketoses(containing a ketone).Is polar as a result of theelectrons spending more timenear the electronegative oxygen atom.Can form hydrogen bonds withwater molecules, helpingdissolve organic compoundssuch as sugars.The carbonyl group ( CO)consists of a carbon atomjoined to an oxygen atom by adouble bond.Fig. 4-10bCHEMICALGROUPSTRUCTURENAME OFCOMPOUNDEXAMPLEFUNCTIONALPROPERTIESAmino Sulfhydryl PhosphateMethylA methyl group consists of acarbon bonded to threehydrogen atoms. The methylgroup may be attached to acarbon or to a different atom.In a phosphate group, aphosphorus atom is bonded tofour oxygen atoms; one oxygenis bonded to the carbon skeleton;two oxygens carry negativecharges. The phosphate group(—OPO32–, abbreviated ) is anionized form of a phosphoric acidgroup (—OPO3H2; note the twohydrogens).PThe sulfhydryl groupconsists of a sulfur atombonded to an atom ofhydrogen; resembles ahydroxyl group in shape.(may bewritten HS—)The amino group(—NH2) consists of anitrogen atom bondedto two hydrogen atomsand to the carbon skeleton.Amines Thiols Organic phosphates Methylated compounds5-Methyl cytidine5-Methyl cytidine is acomponent of DNA that hasbeen modified by addition ofthe methyl group.In addition to taking part inmany important chemicalreactions in cells, glycerolphosphate provides thebackbone for phospholipids,the most prevalent molecules incell membranes.Glycerol phosphateCysteineCysteine is an importantsulfur-containing aminoacid.GlycineBecause it also has acarboxyl group, glycineis both an amine anda carboxylic acid;compounds with bothgroups are called amino acids.Addition of a methyl groupto DNA, or to moleculesbound to DNA, affectsexpression of genes.Arrangement of methylgroups in male and femalesex hormones affectstheir shape and function.Contributes negative chargeto the molecule of which it isa part (2– when at the end ofa molecule; 1– when locatedinternally in a chain ofphosphates).Has the potential to reactwith water, releasing energy.Two sulfhydryl groupscan react, forming acovalent bond. This“cross-linking” helpsstabilize proteinstructure.Cross-linking ofcysteines in hairproteins maintains thecurliness or straightnessof hair. Straight hair canbe “permanently” curledby shaping it aroundcurlers, then breakingand re-forming thecross-linking bonds.Acts as a base; canpick up an H+ fromthe surroundingsolution (water, in living organisms).Ionized, with acharge of 1+, undercellular conditions.(nonionized)(ionized)ATP: An Important Source of Energy for Cellular Processes•One phosphate molecule, adenosine triphosphate (ATP), is the primary energy-transferring molecule in the cell •ATP consists of an organic molecule called adenosine attached to a string of three phosphate groupsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsAdenosineP P P P iP PAdenosine AdenosineEnergyADPATPInorganic
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