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Functional Groups. Functional groups. Components of organic molecules that are involved in chemical reactions give organic molecules distinctive properties ex: male & female hormones…. Types of functional groups. 6 functional groups most important to chemistry of life: hydroxyl u amino
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Functional groups • Components of organic molecules that are involved in chemical reactions • give organic molecules distinctive properties • ex: male & female hormones…
Types of functional groups • 6 functional groups most important to chemistry of life: • hydroxyl u amino • carbonyl u sulfhydryl • carboxyl u phosphate • Affect reactivity • hydrophilic • increase solubility in water
Hydroxyl • –OH • organic compounds with OH = alcohols • names typically end in -ol • ethanol
Carbonyl • C=O • O double bonded to C • if C=O at end molecule = aldelhyde • if C=O in middle of molecule = ketone
Carboxyl • –COOH • C double bonded to O & single bonded to OH group • compounds with COOH = acids • fatty acids • amino acids
Amino • -NH2 • N attached to 2 H • compounds with NH2 = amines • amnio acids • NH2 acts as base • ammonia picks up H+ from solution
Sulfhydryl • –SH • S bonded to H • compounds with SH = thiols • SH groups stabilize the structure of proteins
Phosphate • –PO4 • P bound to 4 O • connects to C through an O • PO4 are anions with 2 negative charges • function of PO4 is to transfer energy between organic molecules (ATP)
Macromolecules • Smaller organic molecules join together to form larger molecules • macromolecules • 4 major classes of macromolecules: • carbohydrates • lipids • proteins • nucleic acids
Polymers • Long molecules built by linking chain of repeating smaller units • polymers • monomers = repeated small units • covalent bonds
How to build a polymer • Condensation reaction • dehydration synthesis • joins monomers by “taking” H2O out • 1 monomer provides OH • the other monomer provides H • together these form H2O • requires energy & enzymes
How to break down a polymer • Hydrolysis • use H2O to break apart monomers • reverse of condensation reaction • H2O is split into H and OH • H & OH group attach where the covalent bond used to be • ex: digestion is hydrolysis
Carbohydrates • Carbohydrates are composed of C, H, O carbo - hydr - ate CH2O (CH2O)x C6H12O6 • Function: • energy u energy storage • raw materials u structural materials • Monomer: sugars • ex: sugars & starches
Sugars • Most names for sugars end in -ose • Classified by number of carbons • 6C = hexose (glucose) • 5C = pentose (fructose, ribose) • 3C = triose (glyceraldehyde)
Simple & complex sugars • Monosaccharides • simple 1 monomer sugars • glucose • Disaccharides • 2 monomers • sucrose • Polysaccharides • large polymers • starch
Building sugars • Dehydration synthesis monosaccharides disaccharide | glucose | glucose | maltose glycosidic linkage
Building sugars • Dehydration synthesis monosaccharides disaccharide | glucose | fructose | sucrose glycosidic linkage structural isomers “Let’s go to the video tape!” (play movie here)
Polysaccharides • Polymers of sugars • costs little energy to build • easily reversible = release energy • Function: • energy storage • starch (plants) • glycogen (animals) • building materials = structure • cellulose (plants) • chitin (arthropods & fungi)
Cellulose • Most abundant organic compound on Earth
Glycemic index • Which food will get into your blood more quickly? • apple • rice cakes • corn flakes • bagel • peanut M&M
Glycemic index • Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels • Carbohydrate foods that breakdown quickly during digestion have the highest glycemic indices. Their blood sugar response is fast & high.
Glycemic index • Which food will get into your blood more quickly? • apple 36 • rice cakes 82 • corn flakes 84 • bagel 72 • peanut M&M 33
Lipids • Lipids are composed of C, H, O • long hydrocarbon chain • Diverse group • fats • phospholipids • steroids • Do not form polymers • big molecules made of subunit smaller molecules • not a continuing chain
Fats • Structure: • glycerol (3C alcohol) + fatty acid • fatty acid = long HC “tail” with COOH group at “head” dehydration synthesis
Fat • Triacylglycerol • 3 fatty acids linked to glycerol • ester linkage = between OH & COOH
Fats • Long HC chain • polar or non-polar? • hydrophilic or hydrophobic? • Function: • energy storage • very rich • 2x carbohydrates • cushion organs • insulates body • think whale blubber! “Let’s go to the video tape!” (play movie here)
Saturated fats • All C bonded to H • No C=C double bonds • long, straight chain • most animal fats • solid at room temp. • contributes to cardiovascular disease (atherosclerosis) = plaque deposits
Unsaturated fats • C=C double bonds in the fatty acids • plant & fish fats • vegetable oils • liquid at room temperature • the kinks made by double bonded C prevent the molecules from packing tightlytogether
Phospholipids • Structure: • glycerol + 2 fatty acids + PO4 • PO4 negatively charged • other small molecules may also be attached • adenine (ATP)
Phospholipids • Hydrophobic or hydrophilic? • fatty acid tails = hydrophobic • PO4 = hydrophilic head • dual “personality” • interaction with H2O is complex • & very important!
Phospholipids in water • Hydrophilic heads attracted to H2O • Hydrophobic tails “hide” from H2O • self-assemble into aggregates • micelle • liposome • early evolutionary stage of cell?
Why is this important? • Phospholipids define outside vs. inside • Where do we find phospholipids in cells? • cell membranes
Phospholipids & cells • Phospholipids of cell membrane • double layer = bilayer • hydrophilic heads on outside • in contact with aqueous solution • hydrophobic tails on inside • form core • forms barrier between cell & external environment
Steroids • ex: cholesterol, sex hormones • 4 fused C rings • different steroids created by attachingdifferentfunctional groups to rings cholesterol
Cholesterol • Important cell component • animal cell membranes • precursor of all other steroids • including vertebrate sex hormones • high levels in blood may contribute to cardiovascular disease
Cholesterol helps keep cell membranes fluid & flexible