chapter 4. the chemistry of carbon. why study carbon? all living things are made of cells cells...

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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