1 Unit III: Biochemistry A. Biological Macromolecules B. Metabolism

2 Biological MacromoleculesLipids Carbohydrates Proteins (4. Nucleic Acids – not covered in this class)

3 What will we learn about each Macromolecule….Structure and Function Metabolic Importance Nutrition and Medical Implications

4 Ch 15 Lipids

5 What are lipids? Group of molecules not defined by structure but by common characteristics non-polar, soluble in non-polar solvents like methylene chloride, gasoline, ether Not soluble in A polar solvent like water….

6 Types of Lipids 1. Fatty Acids 2. Fats and Oils 3. Waxes (structural recognition only) 4. Steroids 5. Phospholipids 6. Fat soluble Vitamins (know basics)

7 Lipids and Health BMI: Body Mass Index: Height vs weightSimple measure to label patients in rubrics ranging from underweight (anorexia/malnutrition…) to overweight (obese) how to measure BMI Blood Lipids: blood lipid panel measures cholesterol, LDL, HDL, triglycerides (heart attack risk?)

8 Blood Lipids Blood Lipids Blood Lipid Panels from Blood Tests

9 CAD- Coronary Artery DiseaseLipid deposits clogging arteries in the body and heart CAD intro Risk Factors for CAD Hypertension, Diabetes, elevated cholesterol smoking sedentary lifestyle stress obesity male sex family history older age Type A personality

10 Monomer/Polymer of TriglyceridesMonomer: Fatty acid, glycerol (phosphate) Macromolecule: Triglyceride (fats/oils), Phospholipids No true polymers….other lipid classes do not have a typical monomer/polymer relationship!!!

11 1. Fatty Acids Long chain hydrocarbons with a carboxylic acid on C#1Opposite end is called the Omega end Know prefixes from 11 – 20 IUPAC: 12 – dodec: Dodecanoic Acid

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13 Fatty Acids are…. Aliphatic molecules:hydrophobic (hydrocarbon) as well as hydrophilic (carboxyl) hydro- philic hydrophobic Hydrocarbon is longer/stronger makes molecule overall hydrophobic

14 Common names of 4 saturated Fatty AcidsC12 – Dodecanoic Acid: Lauric Acid C14 – Tetradecanoic Acid: Myristic Acid C16 – Hexadecanoic Acid: Palmitic Acid C18 – Octadecanoic Acid: Stearic Acid Mnemonic: Lipids Make People Survive!

15 Lipids Make People SurviveFatty Acids to know… Lauric Acid (C12) Myristic Acid (C14) Palmitic Acid (C16) Stearic Acid (C18) Lipids Make People Survive

16 Types of Fatty Acid Saturated FA: only single bonds between CarbonsUnsaturated FA: have some double bonds between Carbons a. trans double bonds

17 Unsaturated FA b: cis-double bondsPolyunsaturated FA: omega fatty acids alternating 2 single with 1 cis-double bds forms ‘omega’ like loops Carboxyl omega end

18 Shapes of Unsaturated Fatty Acids

19 Physical Properties of Fatty AcidsSaturated/Trans fatty Acids highest melting point (Ex: Stearic Acid: 69oC) Perfect alignment: high Van de Waals intermolecular attractions Trans fatty acids do not naturally exist, man made product Are the most stable fatty acids

20 Physical Properties of Fatty AcidsUnsaturated fatty acids lower MP due to kinks: low Van de Waals (example Oleic Acid: MP 13oC) Less stable: double bonds can break! Fatty acid goes rancid… In nature all unsaturated FA have cis-bonds Cis-double bonds start either at omega-3 or omega 6 carbon

21 Physiologically Important Fatty Acid Metabolites1. Omega 6 and 3 FA, are essential fatty acid: limited production in body, need to be absorbed from food 2. Arachidonic Acid AA C 20:4 Omega-6 FA Precursor for Prostaglandins PG

22 Prostaglandins - PG Hormone-like lipids with regulatory functions: PG1: heart rhythm, blood clotting, stomach lining PG2: inflammation

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24 Why do we care?

25 Videos NSAID effect and side effect stomach side effect

26 Warm -up Draw in Kekule a Tridecanoic Acid Lauric AcidOctadecanoic Acid 1. Which one has the highest boiling pt? 2. Which one is also called stearic acid?

27 IUPAC of unsaturated Fatty AcidsΩ C# C#18 α-C (first next to carboxyl) C 18 : 4n -3 C: 18 means its a Fatty Acid with 18 carbons 4n means it has 4 double bonds -3 means first double bond at Ω Carbons #3 Always draw FA from the omega end!!!

28 Draw C18:1n-6 C18:1n-6 trans C16:4n-3

29 Warm-up: Draw An ester between Decanol and Stearic acidWhat lipid class does the resulting molecule belong to?