Lipids *organic molecules with long hydrocarbon chains (nonpolar) Major functions in the body: * energy storage * insulate and protect organs * form cell membranes * hormones

1. Fats and oils – esters composed of glycerol (1,2,3-propanetriol) and long-chain carboxylic acids. Triglycerides

R - usually a straight chain - usually an even number of carbon atoms - between 10 & 20 carbon atoms - no other functional groups present Saturated Fats Unsaturated Fats All single bonds C-C contains C=C and/or C=C Animal fats vegetable oils Solids (high mp) Liquids (lower mp) Pack closely together not closely packed

Essential fatty acids – there are 2 Lipases – enzymes in the body that hydrolyze fats to glycerol and fatty acids. Fatty acids are then broken down to make CO2, H2O and energy. Produce large amounts of energy compared to proteins and carbohydrates (gram for gram) Essential fatty acids – there are 2 Omega-6 linoleic Cis,cis-9,12-octadecadienoic acid Omega-3 linolenic From these, the body can synthesize longer and more unsaturated fatty acids. Trans fatty acids increase formation of LDL

Iodine Number – I2 reacts with pi bonds Iodine Number – I2 reacts with pi bonds. I2 is added to a fat – the more I2 reacts, the more pi bonds present (more unsaturated)

Saponification – the production of soap from fatty acids. Base Hydrolysis – triglyceride is hydrolyzed in the presence of a strong base (OH-) – produces glycerine and conjugate bases of carboxylic acids (soap molecules). Action of soaps – Form micelles to attract nonpolar dirt into polar water.

Hard Water – Resists solution of soap (bubbles not produced) - contains Ca2+ and Mg2+ ions, which precipitate the ions of soap. Phospholipids – contain polar and nonpolar ends (like soap) – form bilayers in cell membranes. embedded proteins – allow for transport of substances into and out of the cell.

Waxes – monohydroxy alcohols - low melting solids - waterproof coating (fruits, some animals) Steroids – A group of molecules with a common fused 4-ring structure

Cholesterol – multifunctional found in tissues, blood, brain, spinal cord building block for other steroids formed in liver, available in food hardening of arteries – heart disease transported by lipoproteins LDL – low density lipoproteins (“bad” cholesterol) – source is saturated fats. - large molecules (18-25 nm long) - transport cholesterol to arteries, leading to cardiovascular diseases.

HDL – high density lipoproteins (“good” cholesterol) - can remove cholesterol from arteries and transport it back to liver. - smaller molecules (8-11 nm long)

Metal Ions in the Body Ca – bones and teeth (needs P to attach) Mg, Na, K – ions in fluids in and around cells. Transition metals – REDOX reactions - Lewis Acids Zn2+ - cofactor in 100 enzymes In insulin Co3+ - vitamin B12 Fe – hemoglobin Cu – cytochrome Mn – needed for healthy bones Cr – helps in metabolism

Sodium/Potassium – transmission of nerve impulses. K+ - most abundant ion inside cells Responsible for cellular enzymes Na+ - most abundant ion outside cells Maintains water balance BOTH regulate H+ ions in the body

Vitamins Required by Body Metabolism Protect health Proper growth Generally act as catalysts/cofactors (coenzymes) Combine with proteins to form enzymes

Fat Soluble Vitamins Water Soluble Vitamins (nonpolar) (polar) A (retinol) B vitamins D (calciferol) C (ascorbic acid) E K Stored in body fat cannot be stored

Excellent source of vitamins and minerals Fruits and Vegetables Excellent source of vitamins and minerals Problems with cooked vegetables: Water soluble vitamins – dissolve in boiled water, don’t make it to body. High temperatures – change molecules (either denaturation occurs, or molecules react)