Carbon and the Molecular Diversity of Life Unit 1 Chapter 4

Why study Carbon? All living things are made of carbon Cells 72% H2O 3% salts (Na, Cl, K…) 25% carbon compounds carbohydrates lipids proteins nucleic acids

Tetravalent Electron Configuration Allows it to make large, complex molecules. Gives covalent compatibility with hydrogen, oxygen, nitrogen, and other carbon atoms. Determines an organic molecule’s 3-dimensional shape

Hydrocarbons Molecules containing only C and H Nonpolar, hydrophobic Can undergo reactions that release large amounts of energy EX: methane, fatty acid tails

Isomers Molecules with same molecular formula but different structures and chemical properties Three Different types: Structural Cis-trans (Geometric) Enantiomers

Structural Isomers Molecules differ in covalent arrangement of atoms Same molecular formula but different covalent arrangements

Cis-trans (geometric) Molecules differ in arrangement around C=C double bond same covalent partnerships

Enantiomers Isomers that are mirror images of each other Important in pharmaceutical industry Enantiomers of Methamphetamine One is drug, other is over the counter in nasal decongestant

Functional Groups Have specific chemical and physical properties regions of molecules commonly reactive determine the chemical properties of organic molecules

Hydroxyl Group -OH Polar Alcohols Name end in -ol Ethanol Can form hydrogen bonds with water helping dissolve organic compounds

Carbonyl Group -CO carbon double-bonded to oxygen Called: polar ketones: carbonyl group is within a carbon skeleton Aldehydes: carbonyl group is at end of carbon skeleton polar found in sugars

Carboxyl Group -COOH carbon is double-bonded to an oxygen and single-bonded to a hydroxyl group Called: carboxylic acids polar Acts as an acids

Amino Group -NH2 A nitrogen bonded to two hydrogens and carbon skeleton Polar Acts as a base Called amines

Sulfhydryl Group -SH sulfur bonded to hydrogen are called thiols Stabilizes the structure of proteins Cross linking of cysteines in hair proteins maintains curliness or straightness. Straight hair can be curled around curlers to break and re from the cross linking bonds

Phosphate Group -PO4 Phosphate bonded to 4 oxygens Polar Have potential to react with water releasing energy important in cellular energy storage and transfer (ATP)

Methyl -CH3 Carbon double bonded to 3 hydrogens Addition of methyl groups of DNA affects expression