Honors Biology Macromolecules New.pdf

Carbon and Macromolecules AP Biology  Why study Carbon? ▪ All of life is built on carbon ▪ Cells ◆ ~72% H2O ◆ ~25% carbon compounds ▪ carbohydrates ▪ lipids ▪ proteins ▪ nucleic acids...

Carbon and Macromolecules AP Biology  Why study Carbon? ▪ All of life is built on carbon ▪ Cells ◆ ~72% H2O ◆ ~25% carbon compounds ▪ carbohydrates ▪ lipids ▪ proteins ▪ nucleic acids ◆ ~3% salts AP Biology ▪ Na, Cl, K…  Chemistry of Life ▪ Organic chemistry is the study of carbon compounds ▪ C atoms are versatile building blocks ◆ bonding properties ◆ 4 stable covalent bonds H C H H H AP Biology  Complex molecules assembled like TinkerToys AP Biology  Hydrocarbons ▪ Combinations of C & H ◆ non-polar ▪ not soluble in H2O ▪ hydrophobic methane ◆ stable (simplest HC) ◆ very little attraction between molecules ▪ a gas at room temperature AP Biology  Hydrocarbons can grow AP Biology  Isomers ▪ Molecules with same molecular formula but different structures (shapes) ◆ different chemical properties ◆ different biological functions 6 carbons 6 carbons AP Biology 6 carbons  Diversity of molecules ▪ Substitute other atoms or groups around the carbon ◆ ethane vs. ethanol ▪ H replaced by an hydroxyl group (–OH) ▪ nonpolar vs. polar ▪ gas vs. liquid ▪ biological effects! AP Biology ethane (C2H6) ethanol (C2H5OH)  Viva la difference! ▪ Basic structure of male & female hormones is identical ◆ identical carbon skeleton ◆ attachment of different functional groups ◆ interact with different targets in the body ▪ different effects AP Biology  Macromolecules Building Blocks of Life AP Biology  Macromolecules ▪ Smaller organic molecules join together to form larger molecules ◆ macromolecules ▪ 4 major classes of macromolecules: ◆ carbohydrates ◆ lipids ◆ proteins ◆ nucleic acids AP Biology  Polymers ▪ Long molecules built by linking repeating building blocks in a chain ◆ monomers ▪ building blocks ▪ repeated small units H2 ◆ covalent bonds O HO H HO H Dehydration synthesis HO H AP Biology  How to build a polymer ▪ Synthesis ◆ joins monomers by “taking” H2O out ▪ one monomer donates OH– ▪ other monomer donates H+ ▪ together these form H2O H2 ◆ requires energy & enzymes O HO H HO H enzyme Dehydration synthesis Condensation reaction HO H AP Biology  How to break down a polymer ▪ Digestion ◆ 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 H2 O ◆ requires enzymes HO H ◆ releases energy enzyme Hydrolysis AP Biology Digestion HO H HO H  Large Biological Molecules AP Biology  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, cellulose AP Biology  Sugars ▪ Most names for sugars end in -ose ▪ Classified by number of carbons ◆ 6C = hexose (glucose) ◆ 5C = pentose (ribose) ◆ 3C = triose (glyceraldehyde) H O CH2O CH2O C H H H O O H H C OH H H OH 6H H 5 HO 3OH HO OH HO H H C H OH OH H H AP Biology Glucos Ribos Glyceraldehyde  Sugar structure 5C & 6C sugars form rings in solution AP Biology Carbons are numbered  CH2OH Simple & complex sugars H O H H ▪ Monosaccharides H OH H O O H ◆ simple 1 monomer sugars H OH ◆ glucose Glucose ▪ Disaccharides ◆ 2 monomers ◆ sucrose ▪ Polysaccharides ◆ large polymers ◆ starch AP Biology  Polysaccharides ▪ Polymers of sugars ◆ costs little energy to build ◆ easily reversible = release energy ▪ Function: ◆ energy storage ▪ starch (plants) ▪ glycogen (animals) ◆ structure = building materials ▪ cellulose (plants) ▪ chitin (arthropods & fungi) AP Biology  Cellulose ▪ Most abundant organic compound on Earth ◆ herbivores can digest cellulose ◆ most carnivores cannot digest cellulose ▪ that’s why they eat meat to get their energy & nutrients ▪ cellulose = roughage AP Biology  Lipids ▪ Lipids are composed of C, H, O ◆ long hydrocarbon chain ▪ Diverse group fat ◆ fats ◆ phospholipids ◆ steroids ▪ Do not form polymers ◆ big molecules made of smaller subunits ◆ not a continuing chain AP Biology  Fat subunits ▪ Structure: ◆ glycerol (3C alcohol) + fatty acid ▪ fatty acid = long HC “tail” with COOH group at “head” enzyme dehydration synthesis AP Biology  Fats store energy ▪ Long HC chain ◆ polar or non-polar? ◆ hydrophilic or hydrophobic? ▪ Function: ◆ energy storage ▪ very rich ▪ 2x carbohydrates ◆ cushion organs ◆ insulates body ▪ think whale blubber! AP Biology  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 AP Biology  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 tightly together AP Biology  Phospholipids ▪ Hydrophobic or hydrophilic? ◆ fatty acid tails = hydrophobic ◆ PO4 = hydrophilic head ◆ dual “personality” interaction with H2O is complex & very important! AP Biology  Why is this important? ▪ Phospholipids create a barrier in water ◆ define outside vs. inside ◆ cell membranes AP Biology  Proteins ▪ Most structurally & functionally diverse group of biomolecules ▪ Function: ◆ involved in almost everything ▪ enzymes (pepsin, polymerase, etc.) ▪ structure (keratin, collagen) ▪ carriers & transport (membrane channels) ▪ receptors & binding (defense: antibodies) ▪ contraction (actin & myosin) ▪ signaling (hormones: insulin) ▪ storage (bean seed proteins) AP Biology  Proteins ▪ Structure: ◆ monomer = amino acids ▪ 20 different amino acids ◆ polymer = polypeptide ▪ protein can be one or more polypeptide chains folded & bonded together ▪ large & complex molecules ▪ complex 3-D shape hemoglobin AP Biology Rubisco growth hormones  Building proteins ▪ Peptide bonds ◆ linking NH2 of one amino acid to COOH of another ◆ C–N bond dehydration synthesis pepti AP Biology de  Protein structure & function ▪ Function depends on structure ◆ 3-D structure ▪ twisted, folded, coiled into unique shape peps in hemoglo bin AP Biology collagen  Denature a protein ▪ Unfolding a protein ◆ disrupt 3° structure ▪ pH salt temperature ◆ unravels or denatures protein ◆ disrupts H bonds, ionic bonds & disulfide bridges ◆ destroys functionality ▪ Some proteins can return to their functional shape after denaturation, many cannot AP Biology  Nucleic Acids ▪ Function: ◆ store & transmit hereditary information ▪ Examples: ◆ RNA (ribonucleic acid) ◆ DNA (deoxyribonucleic acid) ▪ Structure: ◆ monomers = nucleotides AP Biology  Nucleotides ▪ 3 parts ◆ nitrogen base (C-N ring) ◆ pentose sugar (5C) ▪ ribose in RNA ▪ deoxyribose in DNA ◆ phosphate (PO4) group AP Biology  RNA & DNA ▪ RNA ◆ single nucleotide chain ▪ DNA ◆ double nucleotide chain ▪ N bases bond in pairs across chains ◆ spiraled in a double helix ▪ double helix 1st proposed as structure of DNA in 1953 by James Watson & Francis Crick (just celebrated 60th anniversary in 2013!) AP Biology  Pairing of nucleotides ▪ Nucleotides bond between DNA strands ◆ H bonds ◆ purine :: pyrimidine ◆ A :: T ▪ 2 H bonds ◆ G :: C ▪ 3 H bonds AP Biology  Information polymer ▪ Function ◆ series of bases encodes information ▪ like the letters of a book ◆ stored information is passed from parent to offspring ▪ need to copy accurately ◆ stored information = genes ▪ genetic information AP Biology  Macromolecule s are Delicious! Any Questions? AP Biology