BIOL 1441 1st Edition Lecture 5 Outline of Last Lecture I Moderation of temperature continued II Expansion upon freezing III Universal solvent IV Section 3 molecular mass V Section 4 pH Outline of Current Lecture I Carbon II Carbon diversity III Functional groups Current Lecture I Carbon Backbone of Biological Molecules a All living organisms are composed of carbon based molecules i Cells 70 95 water ii 5 30 carbon based compounds iii Proteins DNA carbohydrates lipids b Carbon interact with other atoms diversely i Form large complex different molecules c Carbon is source of life i Carbon Cycle 1 Plants use CO2 sunlight starches sugars 2 ENERGY O2 d Organic Chemistry Study of carbon compounds i Any compound containing carbon organic ii Simplex or complex iii Contain H atoms These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II iv of major elements C H O N S P found in similar proportions between organisms Carbon Diversity a Bonds to 4 other atoms b Electron configuration determines the kinds and number of bonds an atom will form with other atoms c Carbon Bonds i 4 valence electrons ii Forms 4 covalent bonds tetravalence 1 Large complex molecules possible iii Single covalent bond one electron shared 1 Molecules with multiple carbons each C bonds to 4 other atoms 2 Tetrahedral shape angles 109 5 iv 2 carbon atoms joined by a double bond molecule has a flat shape 1 Share 2 electrons same plane v Electron configuration allows covalent compatibility with many different elements 1 Most frequent partners hydrogen oxygen nitrogen 2 Examples a CO2 b O C O c C makes 2 double covalent bonds d Total of 4 covalent bonds e Urea CO NH2 2 d Molecular Diversity Carbon Skeleton i Skeletons vary ii Straight branched rings iii Length iv Double bonds number location v Change the carbon skeleton change the shape structure e Hydrocarbons i Organic molecules consist of only carbon hydrogen ii Lipids or fats iii Hydrophobic do they cross cell membranes iv Petroleum fossil fuel v Partially decomposed remains of organisms millions of yrs ago vi Hydrocarbons can undergo reactions that release a large amount of energy vii Body stores fat f Isomers i Compounds with same molecular formula but different structures and properties 1 Structural III 2 Geometric 3 Enantiomers ii Structural Isomers 1 Have different covalent arrangements of their atoms or location of double bond 2 C8H8 18 possible structures 3 C20H43 366 319 possible structures 4 Geometric Isomers a Have the same covalent arrangements but differ in spatial arrangements b Inflexibility of double bonds 5 Enantiomers a Isomers that are mirror images of each other b Asymmetric carbon attached to 4 different atoms or groups of atoms c Can be arranged in 2 different ways d One biologically active other inactive 6 Enantiomers Pharmaceutical Co a Not equally effective b L dopa Parkinson s Disease c D dopa not effective d Harmful Thalidomide 50 60 s e Mixture of enantiomers pregnant women i Reduced morning sickness ii Severe birth defects Functional Group chemical groups that affect molecular function a Contribute by affecting molecules shape b Directly involved in chemical reactions c Each functional group participates in chemical rxn s in a characteristic way d Functional Groups reactive functional groups hydrophilic increase solubility of organic compounds in water i Hydroxyl group OH 1 Hydrogen atom bonded to oxygen 2 Name alcohols names usually end in ol 3 Functional properties a Polar result of the electronegative oxygen atom drawing electrons toward itself b Attracts water molecules helping dissolve organic compounds ii Carbonyl group 1 Carbon double bonded to oxygen 2 Names a Ketone carbonyl group is within a carbon skeleton iii iv v vi vii b Aldehyde carbonyl group is at the end of the carbon skeleton 3 Functional properties a May be structural isomers with different properties Found in sugars Carboxyl group COOH 1 Carbonyl group and a hydroxyl group 2 Name carboxylic acids organic acids 3 Functional properties a Acidic properties source of H b Covalent bond between O and H so polar that H dissociate reversibly Amino group NH2 1 Amine and a carboxylic acid compounds with both groups are called amino acids 2 Name amines 3 Functional properties a Acts as a base can pick up a H from the surrounding solution b Ionized charge of 1 under cellular conditions Sulfhydryl group SH 1 May be written HS2 Name thiols 3 Functional properties a 2 sulfhydryl groups can interact to help stabilize protein structure Phosphate group OPO321 Name organic phosphates 2 Functional properties a Makes the molecule an anion negative charge b Potential to react with H2O release energy 3 Adenosine triphosphate ATP a Organic phosphate molecule energy source b Adenosine attached to 3 phosphate groups Methyl group not reactive contributes to function by affecting shape CH3 1 Name methylated compounds 2 Functional properties a Affects the expression of genes i Transcription copy DNA into RNA ii Translation translate RNA to protein b Shape can change function