Chapter 9

Carbon Chemistry

Ch 9.1 – Simple Organic Compounds

A. All living things on Earth are made of organic compounds –contain carbon and associated with living (or once living) organisms

B. A compound containing only carbon and hydrogen atoms is a hydrocarbon

1. Methane – the primary component of natural gas, is the simplest hydrocarbon

a) Chemical formula – CH4

b) The molecule contains 4 single covalent bonds

2. If one H is removed from a methane molecule –CH3 remains which is known as a methyl group

a) If two methyl groups bond together they form ethane C2H6

b) Methane and ethane are saturated hydrocarbons

Formation of Ethane

C. Saturated hydrocarbons – have single covalent bonds between every atom in the molecule

1. Known as saturated because have no remaining places for any additional hydrogen atoms to bond

2. Molecule names all end with -ane suffixes

3. Other examples include propane (C3H8) and butane (C4H10)

4. Short hydrocarbon chains have low boiling points which evaporate and burn easily making them good fuels

5. Longer hydrocarbons are found in oils and waxes; these extremely long chains make up many carbohydrates

D. Unsaturated hydrocarbons – have double or triple covalent bonds between carbon atoms therefore are not filled with hydrogen at every bonding site

1. Double bonds

a) Names end with –ene

b) Ethene (C2H4) – has a double bond between the carbons

2. Triple bonds

a) Names end with –yne

b) Acetylene (C2H2) – has a triple bond between the carbons; used in welder’s torches

E. Isomers – hydrocarbons with the same chemical formula but different structures

1. Ex: Butane & Isobutane

F. Hydrocarbons in a circular structure can contain one or more double bonds

1. Names contain the prefix cyclo-

2. Ex: cyclohexane

(Hexane)

Ch 9.2 – Other Organic Compounds

A. Substituted hydrocarbons –have a hydrogen atom replaced with something else

1. Alcohols – form when a hydrogen is replaced with a hydroxyl group (an oxygen and hydrogen covalently bonded –OH)

a) Methanol (CH3OH) – AKA wood alcohol; used in antifreeze

CH3 + OH CH3OH

b) Ethanol (C2H5OH) - AKA drinking alcohol; made naturally when sugar in corn, grains or fruits ferments; also used as fuel additive

c) Isopropyl alcohol (C3H7OH) – AKA rubbing alcohol; used commonly as a disinfectant

2. Carboxylic Acids – form when a hydrogen is replaced by a carboxyl group (-COOH)

a) Found in the stings and bites of many insects

b) Also common in many foods such as fruits and vinegar

Acetic Acid

3. Amines – form when a hydrogen is replaced by an amino group (-NH2)

a) Methylamine (CH3NH2) – responsible for strong odor in cheese

4. Amino Acids – form when 2 hydrogen are replaced, one by an amino group and the other by a carboxyl group

a) Amino acids are the building blocks of proteins

b) Ex: Glycine & Alanine

(There are 20 different types)

Ethane based substituted hydrocarbons

Ch 9.3 – Biological Compounds

A. Polymer – a molecule made of many small organic molecules linked together by covalent bonds

1. The small molecules that form polymers are called monomers

2. The chemical reaction that bonds these monomers is called polymerization

B. Proteins – polymer consisting of a chain of individual amino acids linked together

1. There are 20 different amino acids

2. Make up many structures in the body such as muscles, tendons, ligaments, hair, fingernails and hemoglobin

2. Some proteins are made in the body while others must be obtained by food

C. Carbohydrates – polymer consisting of only carbon, hydrogen and oxygen

1. Sugars – simple carbs containing only 5, 6 or 7 carbon atoms arranged in a ring shaped structure

a) Ex: glucose, fructose, sucrose

Other Sugars

2. Starches – complex carbs made of hundreds of sugar molecules

3. Fiber – carb made of glycogen (glucose molecules) that forms cellulose in plant cell walls

a) Cannot be used by humans as an energy source but other animals such as cows can

D. Lipids – contain the same elements as carbohydrates but in a different arrangement

1. Endothermic reactions form lipids so when bonds between the atoms contain a large amount of energy which can be released if broken

2. Two types of lipids

a) Saturated lipids – come from animals and are typically solids; have all single bonds in straight chain

b) Unsaturated lipids – come from plants and are typically liquids; have a bent chain where double bonds occur

E. Cholesterol –complex lipid present in foods that come from animals

1. Can cause atherosclerosis is too much is present in the bloodstream