Unit 1 – The Chemistry of Life Chapter 4 ~ Carbon & The Molecular Diversity of Life

Organic chemistry Chemistry that contains the element carbon –tetravalenc –tetrahedron – 4 covalent bonds –shape determines function

Hydrocarbons Only carbon & hydrogen (petroleum; lipid ‘tails’) Covalent bonding; nonpolar High energy storage (fossil fuels) –Examples include fats, petroleum, oils, fuel

Isomers same molecular formula, but different structure & properties C 4 H 10 shown has two isomers; butane and isobutane respectively Structural isomers –# of possible combinations increases

Geometric differing spatial arrangement due to inflexibility of double bonds Slight difference in shape btw geometric isomers can dramatically affect the biological activities of organic molecules.

Enantiomers mirror images Important in pharmacological industry Cells can generally tell the difference between the two type –One is useful and the other is generally not (borderline harmful in some cases) –Example: in the 1960’s the drug thalidomide was prescribed to pregnant women; one version of enantiomer was a sedative, the other caused birth defects

Three types of isomers. Figure 4.6, page 52

Importance of enantiomers. The molecule on the right is of medical importance to Parkinson’s patients, while the molecule on the right can cause birth defects.

Functional Groups, I Attachments that replace one or more of the hydrogens bonded to the carbon skeleton of the hydrocarbon Each has a unique property from one organic to another Hydroxyl Group H bonded to O; alcohols; polar (oxygen); solubility in water Carbonyl Group C double bond to O; At end of HC: aldehyde Otherwise: ketone

Functional Groups, II Carboxyl Group O double bonded to C to hydroxyl; carboxylic acids; covalent bond between O and H; polar; dissociation, H ion Amino Group N to 2 H atoms; amines; acts as a base (+1) Sulfhydral Group sulfur bonded to H; thiols Phosphate Group phosphate ion; covalently attached by 1 of its O to the C skeleton;