1 Macromolecules “The molecules of life”

Organic Chemistry All living things are mostly composed of 6 elements: C, H, N, O, P, S Compounds are broken down into 2 general categories: Inorganic Compounds: –Do not contain carbon Organic compounds –Contain significant amountsof carbon. –Often found with common "functional groups"

Carbon (C) Carbon has 4 electrons in outer shell. Carboncan form covalent bonds with as many as 4 other atoms (elements). Usually with C, H, O or N. 3 Example:CH 4 (methane)

5 Macromolecules LARGE organic molecules. Also called POLYMERS (poly- means “many”) – Made up of smaller “building blocks” called MONOMERS (mono- means“one”) 4 types: 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic acids (DNA and RNA)

Monomer vs. Polymer 5

Macromolecules are formed from Dehydration Synthesis Also called “condensation reaction” Forms polymers by combining monomers by “removing water”. HOH HHHO H2OH2O 6

Macromolecules are broken down by Hydrolysis Separates monomers by “adding water” HOHHHO HOH H2OH2O 7

Carbohydrates Carbohydrates are made from simple sugars like: glucose and fructose. Carbohydrates store energy. Examples: A.monosaccharide B.disaccharide C.polysaccharide 8

Carbohydrates Monosaccharide:one sugar unit Examples: glucose (C 6 H 12 O 6 ) deoxyribose ribose Fructose Galactose glucose

Carbohydrates Disaccharide: two sugar unit Examples: –Sucrose (glucose+fructose) –Lactose (glucose+galactose) –Maltose (glucose+glucose) glucose

Carbohydrates Polysaccharide: many sugar units Examples: starch (bread, potatoes) glycogen ( muscle) cellulose (lettuce, corn) glucose cellulose 11

14 Lipids Not soluble in water (do not dissolve). Functions: –Store the most energy –Make up cell membranes –Act as chemical messengers (hormones) –Protect and insulate Examples: 1.Fats 2.Phospholipids 3.Oils 4.Waxes 5.Steroid hormones 6.Triglycerides

Lipids Triglycerides: composed of 1 glycerol and 3 fatty acids. glycerol fatty acids O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 O C-CH 2 -CH 2 -CH 2 -CH 13 H H-C----O H

Fatty Acids There are two kinds of fatty acids you may see these on food labels: 1. Saturated fatty acids:no double bonds 2. Unsaturated fatty acids:double bonds O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 (bad) saturated O C-CH 2 -CH 2 -CH 2 -CH (good) unsaturated 14

Proteins (Polypeptides) Amino acids (20 different kinds of aa) bonded together by peptide bonds (polypeptides). Functions of proteins: 15 1.Storage: 2.Transport: 3.Regulatory: 4.Movement: 5.Structural: 6.Enzymes: albumin (egg white) hemoglobin hormones muscles membranes, hair, nails cellular reactions

Proteins (Polypeptides) Four levels of protein structure: A.Primary Structure B.Secondary Structure C.Tertiary Structure D.Quaternary Structure 16

Primary Structure aa1aa2aa3aa4aa5aa6 Peptide Bonds Amino acids bonded together by peptide bonds (straight chains) Amino Acids (aa) 20

Secondary Structure 3-dimensional folding arrangement of a primary structure into coils and pleats held together by hydrogen bonds. Twoexamples: Alpha Helix Beta Pleated Sheet Hydrogen Bonds 18

Tertiary Structure Secondary structures bent and folded into a more complex 3-D arrangement of joined poypeptides Bonds:H-bonds, ionic, disulfide bridges (S-S) Call a “subunit”. Alpha Helix Beta Pleated Sheet 19

Quaternary Structure Composed of 2 or more “subunits” Globular in shape Form in Aqueous environments Example: enzymes (hemoglobin) subunits 20

Nucleic acids Carry the genetic information to make proteins. Two types: a.Deoxyribonucleic acid (DNA- double helix) b.Ribonucleic acid (RNA-single strand) Nucleic acids are composed of long chains of nucleotides linked by dehydration synthesis. 21

Nucleic acids Nucleotides include: phosphate group pentose sugar (5-carbon) nitrogenous bases: adenine (A) thymine (T) DNA only uracil (U) RNA only cytosine (C) guanine (G) 22

27 Nucleotide O O=P-O O Phosphate Group N Nitrogenous base (A, G, C, or T) O C1C1 C4C4 C3C3 C2C2 5 CH2 Sugar (deoxyribose)

28 DNA - double helix P P P O O O P P P O O O3O3 5 3 G C TA

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