Organic Compounds

1. Organic Compounds • Organic contain carbon (C)…C6H12O6 • Inorganic  no carbon (except CO2) • Ex. H2O, minerals, salts • Why is carbon unique? • It can form 4 covalent bonds (4e- in outer shell) • Can form extremely long chains or rings by bonding with other atoms

2. Polymerization Building larger molecules from smaller units Monomer= single unit molecule (ex. 1 glucose) Polymer = 2+ monomers strung together (starch)

3. Organic Compound #1:Proteins • 50% of your dry weight! • Made of the elements C, H, O, N • Monomers Amino Acids (20 of them) -There are 3 parts to an a.a. – all bonded to a C atom 1. Amino group (NH2) 2. Carboxyl Group (COOH) 3. “R” group (20 varieties of atoms, gives each a.a. uniqueness) Picture

4. Proteins 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 polypeptides Types: • Structural: skin, hair, nails, muscles • Transport: hemoglobin (O2 trough body) • Enzymes:speed up rxns in cells (up to1 bill X) • Defensive: Antibodies in immune system

6. Organic Compound #2: Carbohydrates C6H12O6 Isomers = same formula, diff. structure • Quick source of energy • Composed of C, H, O (1:2:1) A. Monosaccharides simple sugars, monomers 1. Glucose (plants) 2. Fructose (fruit) 3. Galactose (milk) B. Disaccharides 2 mono’s joined 1. Sucrose(table sugar) = Glucose + Fructose 2. Maltose = Glucose + Glucose C. Polysaccharides 3+ mono’s - Glycogen, Cellulose, Starch, Chitin

7. glucose fructose Two Monosaccharides

8. Two Polysaccharides Starch Cellulose

9. Oleic acid Stearic acid cis double bond causes bending Figure 5.12 (b) Unsaturated fat and fatty acid Figure 5.12 (a) Saturated fat and fatty acid Organic 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 membranes • Insulation • Saturated fatty acids = no double bonds, harder to break down • Unsaturated fatty acids = contain double bonds, easier to break down Interactive Website

10. WATER Hydrophilic head WATER Hydrophobic tail Lipids Continued… • Lipids are non-polar don’t dissolve in water • Types of Lipids: • Triglycerides = 3 fatty acids chains + glycerol • Phospholipids = 2 FA chains + glycerol + PO4 • Cell membranes • Steroids (ex. cholesterol and testosterone) • Wax = FA + alcohol

11. Triglyceride Waxes Phospholipid

12. Trans fats • What are they? • (mainly) Artificially made fats • made by adding hydrogen to vegetable oil (turns liquid oil into solid (shortening) • Why are they so bad? • extremely difficult to break down • linked to raising LDL levels – heart disease • Why are they in food? • Prolongs shelf-life • Aids texture of baked goods

13. Trans fats (cont’d) • What foods tend to have trans fats? • 40% found in baked goods – cakes, cookies, crackers…some in candy. • What’s the FDA’s stance? • Must be on nutrition label (since Jan.1, 2006) • Many companies have altered recipes to eliminate the use of trans fats • Some cities have tried to pass laws that ban restaurants from using trans fats • Things to look for on nutrition label. • (partially) hydrogenated oils = trans fat!

14. Organic Compound #4:Nucleic Acids • DNA & RNA (C,H,O,N,P) • DNA stores genetic info. (instructions for a.a) • RNA transfers info. for making proteins • Monomers nucleotides • There 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)

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

16. Condensation

17. Hydrolysis

18. Carbon Atom Hydrogen Atom

19. Enzymes and Energy • Each cell needs to perform thousands of different chemical rxns…this requires energy • Activation energy minimum amount of energy needed to get a rxn going (energy barrier) • First the bonds in the reactant molecules need to be weakened How 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)

20. This prevents molecules from spontaneously breaking down

21. Enzymes: Biological Catalysts • Enzymes lower the energy barrier…HOW? • Enzyme binds to its specific substratemolecule (the reactant the enzyme fits with) • They are bound at the enzyme’s active site • This bond stretches the substrate into a different shape (transition state) and weakens it’s bonds or brings two reactants into position for a rxn • This is called the INDUCED FIT model • The enzyme is NOT changed by the reaction (can be used over and over)

22. What factors affect enzyme activity? Enzymes become denatured if conditions are not right (usually irreversible). 1. Temperature: if not ideal temp, reaction rates fall 2. pH: most enzymes work best between 6-8 3. Salinity: too much or too little inactivates the enzyme

23. Enzymes and Temperature

24. Enzymes and pH