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Chapter 5. Macromolecules. 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
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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
So what’s all this talk about carbs? Atkin’s Diet South Beach Diet
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)
What functional groups? carbonyl aldehyde ketone hydroxyl
Sugar structure • 5C & 6C sugars form rings in aqueous solutions • in cells! Carbons are numbered
Numbered carbons C 6' C O 5' C C 4' 1' C C 3' 2'
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
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)
Polysaccharide diversity • Molecular structure determines function • isomers of glucose • How does structure influence function…
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
Let’s build some Carbohydrates!