Organic Compounds

Organic CompoundsOrganic contain carbon (C)C6H12O6Inorganic no carbon (except CO2)Ex. H2O, minerals, saltsWhy is carbon unique?It can form 4 covalent bonds (4e- in outer shell)Can form extremely long chains or rings by bonding with other atomsProteins continued.Peptide Bond covalent bond b/w 2 a.a.Polypeptide long chain of a.a. A protein can be made of 1 or more polypeptidesTypes:Structural: skin, hair, nails, musclesTransport: hemoglobin (O2 trough body)Enzymes: speed up rxns in cells (up to1 bill X)Defensive: Antibodies in immune systemOrganic Compound #1:Proteins50% of your dry weight!Made of the elements C, H, O, NMonomers Amino Acids (20 of them)-There are 3 parts to an a.a. all bonded to a C atom1. Amino group (NH2)2. Carboxyl Group (COOH)3. R group (20 varieties of atoms, gives each a.a. uniqueness) Picture

Organic Compound #2: CarbohydratesQuick source of energyComposed of C, H, O (1:2:1) A. Monosaccharides simple sugars, monomers1. Glucose (plants) 2. Fructose (fruit) 3. Galactose (milk)B. Disaccharides 2 monos joined 1. Sucrose (table sugar) = Glucose + Fructose 2. Maltose = Glucose + GlucoseC. Polysaccharides 3+ monos - Glycogen, Cellulose, Starch, ChitinC6H12O6Isomers = same formula, diff. structure

Two Monosaccharides

glucosefructoseTwo Polysaccharides

CelluloseStarchOrganic Compound #3:Lipids (Fats & Oils)C, H, O (more C & H, and less O then carbs)Uses:Long term energy storage (hibernation/migration)Building of cell membranesInsulation Saturated fatty acids = no double bonds, harder to break downUnsaturated fatty acids = contain double bonds, easier to break downInteractive Website

(a) Saturated fat and fatty acidStearic acidFigure 5.12

(b) Unsaturated fat and fatty acidcis double bondcauses bendingOleic acidFigure 5.12

Lipids ContinuedLipids are non-polar dont dissolve in waterTypes of Lipids:Triglycerides = 3 fatty acids chains + glycerolPhospholipids = 2 FA chains + glycerol + PO4Cell membranesSteroids (ex. cholesterol and testosterone)Wax = FA + alcohol

Hydrophilichead WATERWATERHydrophobictail

Triglyceride

Waxes

PhospholipidTrans fatsWhat are they?(mainly) Artificially made fatsmade by adding hydrogen to vegetable oil (turns liquid oil into solid (shortening)Why are they so bad?extremely difficult to break downlinked to raising LDL levels heart diseaseWhy are they in food?Prolongs shelf-lifeAids texture of baked goods

Trans fats (contd)What foods tend to have trans fats?40% found in baked goods cakes, cookies, crackerssome in candy.Whats the FDAs stance?Must be on nutrition label (since Jan.1, 2006)Many companies have altered recipes to eliminate the use of trans fatsSome cities have tried to pass laws that ban restaurants from using trans fatsThings to look for on nutrition label.(partially) hydrogenated oils = trans fat!

Organic Compound #4:Nucleic AcidsDNA & RNA (C,H,O,N,P)DNA stores genetic info. (instructions for a.a)RNA transfers info. for making proteinsMonomers nucleotidesThere are 3 parts to a nucleotide: 1. Phosphate Group (PO4-3) 2. 5-Carbon Sugar (deoxyribose/ribose) 3. nitrogen base (A,T,C,G,U)

Building & Breaking PolymersCondensation (aka Dehydration Synthesis):reaction in which 2 monomers are linked, 1 H2O is removed in the processEx. adding a glucose to a growing starch moleculeHappens with all polymers being built!Hydrolysis Reaction Rxn in which a polymer is broken into monomers ; a H2O is added for each monomer removedEx. removing an amino acid from a protein animation

CondensationHydrolysis

Carbon Atom

Hydrogen AtomEnzymes and EnergyEach cell needs to perform thousands of different chemical rxnsthis requires energyActivation energy minimum amount of energy needed to get a rxn going (energy barrier)First the bonds in the reactant molecules need to be weakenedHow can cells cross this energy barrier?-So cells need to use an enzyme (a biological catalyst that speeds up a chemical reaction)-Enzymes lower the activation energy needed for a rxn to proceed to product(s)

This prevents molecules from spontaneously breaking down Enzymes: Biological CatalystsEnzymes lower the energy barrierHOW?Enzyme binds to its specific substrate molecule (the reactant the enzyme fits with) They are bound at the enzymes active siteThis bond stretches the substrate into a different shape (transition state) and weakens its bonds or brings two reactants into position for a rxnThis is called the INDUCED FIT modelThe enzyme is NOT changed by the reaction (can be used over and over)

What factors affect enzyme activity?Enzymes become denatured if conditions are not right (usually irreversible). 1. Temperature: if not ideal temp, reaction rates fall2. pH: most enzymes work best between 6-83. Salinity: too much or too little inactivates the enzymeEnzymes and TemperatureEnzymes and pH