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Chapter 5. 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 repeating building blocks in a chain monomers building blocks
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Chapter 5 • 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 repeating building blocks in a chain • monomers • building blocks • repeated small units • covalent bonds
H2O HO H HO H enzyme HO H How to build a polymer • Synthesis • http://nutrition.jbpub.com/resources/animations.cfm?id=6 • joins monomers by “taking” H2O out • one monomer donates OH– • other monomer donates H+ • together these form H2O • requires energy & enzymes Dehydration synthesis Condensationreaction
H2O HO H enzyme H HO H HO How to break down a polymer • Digestion • http://nutrition.jbpub.com/resources/animations.cfm?id=7&debug=0 • use H2O to breakdown polymers • reverse of dehydration synthesis • cleave off one monomer at a time • H2O is split into H+ and OH– • H+ & OH– attach to ends • requires enzymes • releases energy Hydrolysis Digestion
sugar sugar sugar sugar sugar sugar sugar sugar Carbohydrates • Carbohydrates are composed of __, __, __ carbo - hydr - ate CH2O (CH2O)x C6H12O6 • Function: • fast energyuenergy storage • raw materialsustructural materials • Monomer: sugars • ex: sugars, starches, cellulose (CH2O)x C6H12O6
Functional groups determine function carbonyl aldehyde carbonyl ketone
Sugar structure 5C & 6C sugars form rings in solution
CH2OH O H H H OH H OH HO H OH Glucose Simple & complex sugars • Monosaccharides • simple 1 monomer sugars • glucose • Disaccharides • 2 monomers • sucrose • Polysaccharides • large polymers • starch
H2O Building sugars • Dehydration synthesis monosaccharides disaccharide | glucose | glucose | maltose
H2O Building sugars • Dehydration synthesis monosaccharides disaccharide | glucose | fructose | sucrose (table sugar)
Polysaccharides • Polymers of sugars • costs little energy to build • easily reversible = release energy • What are they used for? • energy storage • starch (plants) • glycogen (animals) • in liver & muscles • structure • cellulose (plants) • chitin (arthropods & fungi)
CH2OH O OH H H OH H OH H H NH O C CH3 (a) The structure of the chitin monomer. (b) Chitin forms the exoskeleton of arthropods. This cicada is molting, shedding its old exoskeleton and emerging in adult form. (c) Chitin is used to make a strong and flexible surgical thread that decomposes after the wound or incision heals. CHITIN!!!!!!!!!!!!!!
Polysaccharides in cells starch (plant) energystorage glycogen (animal)
Polysaccharides in cells • As starch is being stored, it undergoes hydrolysis reactions (as needed) to release energy.
Polysaccharide diversity • Molecular structure determines function in starch in cellulose • isomers of glucose • structure determines function…
enzyme enzyme Digesting starch vs. cellulose starcheasy todigest cellulosehard todigest only bacteria can digest
Cellulose • Most abundant organic compound on Earth • herbivores contain a mechanism to digest cellulose • most carnivores do not • that’s why they eat meat to get their energy & nutrients • cellulose = “insoluble fiber”
Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet
Helpful bacteria • How can herbivores digest cellulose so well? • BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals