Chapter 2 The Chemistry of Life

Section 3Carbon Compounds

Organic Chemistry The study of all compounds that contains

bonds between carbon atoms

The Chemistry of Carbon Each electron can form with an electron

from another atom to form strong covalent bonds.

Carbon atoms have 4 valence electrons. Carbon can bond with almost any other

element. Carbon atoms can also bond with other

carbon atoms.

Carbon chains Because carbon can bond with other

carbon atoms, it can form chains. Chains can be any length. Carbon – carbon bonds can be single,

double or triple covalent bonds. Chains can form into rings

Methane Acetylene Butadiene Benzene Isooctane

Section 2-3

Figure 2-11 Carbon Compounds

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6

Macromolecules Giant molecules are Formed by polymerization – large

compounds are built by joining smaller ones together.

Monomers are smaller units that join together to form polymers

Four groups of organic compounds (macromolecules) Carbohydrates Lipids Nucleic acids Proteins

Carbohydrates Compounds made up of carbon, hydrogen

and oxygen atoms. Are the main source of energy for living

things. Provides quick energy – easily and quickly

enter the bloodstream

Energy source Simple carbohydrates – sugars such as

glucose, fructose and galactose. Breakdown and give immediate energy for

cell activities. Complex carbohydrates – starches. Living things store extra sugar as starch

Starch

Glucose

Section 2-3

Figure 2-13 A Starch

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Sugars Monosaccharides – single sugar

molecules. Examples: galactose, fructose Polysaccharides – large macromolecules

formed from monosaccharides Examples: glycogen (animal starch). Use: When glucose runs low, glycogen is

released from the liver and provides energy

Sugars, continued Example: Plant starch – stores excess

sugar Example: Cellulose – structural

polysacchride; gives plants strength and rigidity

Lipids Fats, oils, waxes, steroids Not water soluble Made mostly from carbon and hydrogen

atoms Contains some oxygen atoms Steroids – cholesterol, bile, cortisone, sex

hormones (testosterone, progesterone)

Lipids Saturated fats – contain the maximum

amount of H atoms; Ex. Meat and dairy products

Unsaturated fats – contains one carbon-carbon double bond Ex. Nuts, vegetable oil, fish

Polyunsaturated – contains more than one carbon-carbon double bond. Ex. Cooking oils

Lipids Functions in living organisms include:

Energy source (slow breakdown) Insulation Cushion and protect organs Component of membranes (phospholipids) Chemical messengers – send information

between cell organelles and other cells

Nucleic Acids Macromolecules containing hydrogen,

oxygen, nitrogen, carbon and phosphorous.

Composed of nucleotides Nucleotides – consist of a 5-carbon

sugar, a phosphate group, and a nitrogenous base.

Nucleic acids Store and transmit genetic information Two kinds:

RNA – ribonucleic acid DNA – deoxyribonucleic acid

Proteins

Macromolecules that contain nitrogen as well as carbon, hydrogen and oxygen.

Are polymers of molecules called amino acids (20 different amino acids)

(Translation – proteins are chains of amino acids linked together by peptide bonds)

General structure Alanine Serine

Section 2-3

Figure 2-16 Amino Acids

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Amino group Carboxyl group

Amino Acids DNA contains the instructions for

arranging amino acids into proteins. Each protein has a different role:

Control rate of reactions within a cell Regulate cell processes Form bones and muscles Transport substances into or out of cells to

help fight disease

Aminoacids

Section 2-3Figure 2-17 A Protein

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Assignment Make a compare/contrast table entitled:

Four Groups of Organic Compounds Column Titles are:

Group Name Chemical Composition Examples Functions in Living Things