BIOS 208 1st Edition Lecture 7Outline of Last Lecture I. Covalent BondsII. Oxygen O2III. Ionic BondsIV. Carbon and the Molecular Diversity of Life V. The End of Vitalism in ChemistryOutline of Current Lecture I. Urea Structure and Stanley Miller’s ExperimentII. Carbon based compoundsIII. Hydrocarbon structuresIV. Isomers: Structural and GeometricV. Stereo IsomersVI. Functional GroupsVII. HydroxylVIII. CarbonylIX. CarboxylCurrent LectureI. Urea Structure and Stanley Miller’s ExperimentA. CH4N2O.B. A compound formed in the liver from ammonia produced by the deamination of amino acids.C. Principal end product of protein catabolism and constitutes about one half of the total urinary solids.D. Could early Earth atmosphere have produced organic molecules from abiotic components?E. Hydrogen, Methane ammonia and water.F. Electrical discharge (lightning).G. Produced hydrocarbons, amino acids, formaldehyde and HCN.H. These are organic molecules, an early stage in the origin of life.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. Carbon based compoundsA. Carbon can make 4 covalent bonds.B. Simple organic molecules contain only H and C, and are termed Hydrocarbons.C. e.g. methane CH4.D. Generally hydrocarbons are not polar or hydrophilic; they are repelled by water and are hydrophobic.E. Some small hydrocarbons are gases, and can contain single, double or triple bonds…methane, ethane, ethene, acetylene. Molecular models show specific shapes.F. Hydrocarbons form “backbones” of larger biological molecules.G. E.g. fats and proteins.I. Hydrocarbon structuresA. Some hydrocarbons make straight chain molecules of increasing length, but they can also branch to form isomers.B. Isomers have the same formula but different structures…e.g. butane and isobutane are both C4H10.C. Some hydrocarbons can have isomers based uponwhere their double bond is located.a) E.g. 1-butene, 2-butene.D. Certain hydrocarbons also form cyclic structures which form rings.b) E.g. cyclohexane (single bonds) and benzene (alternating single and double bonds).II. Isomers: Structural and GeometricA. Structural isomers have the same empirical formula, but a different arrangement of bonds.a) C5H12.B. Geometric isomers must have: b) A C=C double bond (no rotation around this bond).c) Different substituents are on the carbons: can be on the same side, or across from each other.d) C2H2Cl2.III. Stereo IsomersC. Also called Enantiomers are related to each other by mirror symmetry D. Like left and right hands. E. An asymmetric carbon must be present (i.e., a carbon with 4 different substituents)F. L-alanine and D-alanine are amino acids. G. Only the L-form is used to make proteins.H. They are mirror image molecules.IV. Functional GroupsA. Distinctive properties of organic molecules depend on the carbon skeleton and on the molecular components attached to it.B. A number of characteristic groups can replacethe hydrogens attached to skeletons of organicmolecules.C. Functional groups are the components of organic molecules that are most commonly involved in chemical reactions.D. The number and arrangement of functional groups give each molecule its unique properties.E. Some function groups include:a) Hydroxyl1. Alcohols= usually end in -ol.2. Is polar as a result of the electrons spending more time near the electronegative oxygen atom.3. Can form hydrogen bonds with water molecules, helping dissolve organic compounds such as sugars.b) Carbonyl1. Ketones if the carbonyl group is within a carbon skeleton.2. A ketone and an aldehyde may be structural isomers with different properties, as is the case for acetone and propanal.3. Ketone and aldehyde groups are also found in sugars, giving rise to two major groups of sugars: ketoses(containing ketone groups) and aldoses(containing aldehyde groups).c) Carboxyl1. Carboxylic acids or organic acids.2. Acts as an acid; can donate an H+ because the covalent bond between oxygen and hydrogen is polar.3. Found in cells in the ionized form with a charge of 1– and called a carboxylate
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