Chapter 4.Chapter 4.
The Chemistry of The Chemistry of CarbonCarbon
Why study Carbon?Why study Carbon?All living things are made of cells Cells
◦~72% H2O ◦~3% salts (Na, Cl, K…)◦~25% carbon compounds
◦carbohydrates◦ lipids◦proteins ◦nucleic acids
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Chemistry of LifeChemistry of Life
Organic chemistry is the study of carbon compounds
C atoms are versatile building blocks◦bonding properties◦4 stable covalent bonds -
pair of electrons are shared
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Complex molecules assembled like –candy & toothpicks
HydrocarbonsHydrocarbonsSimplest Carbon molecules =
hydrocarbons ◦A compound with a combination of Carbon &
Hydrogen
Simplest HC molecule = methane◦1 carbon bound to 4 H atoms◦stable◦a gas at room temperature
Hydrocarbons can growHydrocarbons can grow
adding C-C bonds◦straight line
ethane hexane
◦branching isohexane
◦ring cyclohexane
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ethane
hexane
cyclohexaneisohexane
methane
Diversity of organic moleculesDiversity of organic molecules
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IsomersIsomersMolecules with same molecular formula
but different structures ◦different chemical properties – C6H14
Various kinds of isomersVarious kinds of isomersMolecules differ in structural
arrangement of atoms
Around a double bond – alkenes
Isomers of ethene
Three of the four classes of macromolecules form chainlike molecules called polymers.◦Polymers consist of many similar or identical
building blocks linked by covalent bonds.
The repeated units are small molecules called monomers. (like links of a chain)
Most macromolecules are polymersMost macromolecules are polymers
4 MAIN MACROMOLECULES4 MAIN MACROMOLECULES
MOLECULE MONOMER USESProteins (amino acids) support/motionLipids (glycerol & fatty acids) energy storage/insulation
Carbohydrates (monosaccharides) quick energyNucleic acids (nucleotides) store information
• They all contain CARBON and are called ORGANIC molecules (Also hydrogen, oxygen are in all of them)
Diversity of moleculesDiversity of moleculesSubstitute other atoms or groups
around the C◦ethane vs. ethanol
H replaced by an hydroxyl group (–OH)
ethanolethane
What element is the blue one above? How many bonds does it form?
HydroxylHydroxyl
–OH◦organic compounds with OH = alcohols ◦names typically end in -ol
ethanol
More on More on Functional GroupsFunctional Groups
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Types of functional groupsTypes of functional groups
6 functional groups most important to chemistry of life:◦hydroxyl amino◦carbonyl sulfhydryl◦carboxyl phosphate
Affect reactivity◦hydrophilic ◦increase solubility in water◦Change all kinds of properties
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Carboxyl Carboxyl
–COOH ◦C double bonded to O & single bonded to OH
group compounds with COOH = acids
◦fatty acids◦amino acids
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AminoAmino
-NH2 ◦N attached to 2 H
compounds with NH2 = amines◦amnio acids
NH2 acts as base ◦ammonia picks up H+ from solution
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Viva la difference!Viva la difference!Basic structure of male & female
hormones is identical◦identical C skeleton ◦attachment of different functional groups◦interact with different targets in the body
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