What makes McDonald’s fries taste SOOOO good?

Lipids Macromolecules: Fats, Waxes and Oils. Lipids are composed of C, H, and O Greater H:O ratio than 2:1 Primary function is energy storage. Energy is stored in C-H bonds. More efficient in storing energy than carbohydrates Other functions: waterproofing, membranes in cells, hormones Macromolecules: Fats, Waxes and Oils.

Structure (building blocks) Lipids are made of 2 parts 1 Glycerol - an alcohol - Serves as backbone of the molecule 3 Fatty acids - Long hydrocarbon chains connected to a carboxyl group

Dehydration Synthesis of a Lipid

Hydrolysis of a Lipid

Types of fats Saturated fats have long chains with no double-bonds, solid at room temperature. Ex: beef fat Unsaturated fats have double bonds, liquid at room temperature. Ex: corn oil (unsaturated trans fats are linked to heart disease) Polyunsaturated fats have many double bonds Each time a double bond is encountered, the molecule "Bends" slightly, resulting in a lower density of the lipid. This makes the molecule more likely to remain liquid at room or body temperatures. And thus, less likely to clog cardiac arteries.

Other Lipids 4 Other types of biologically important Lipids Phospholipids - Important for membrane structure Steroids - eg. Cholesterol & testosterone. Provide membrane support / serve as hormones Terpenes - serve as important components of pigments Prostaglandins - appear to act like localized hormones to induce cellular/tissue responses

Polar Molecule: the ends of the molecule carry an unequal charge Polar molecules mix well with each other. Remember like mixes well with like molecules. Ex: Water and ethanol, both polar, create a homogeneous solution. Polar molecules are water soluble

Non Polar Molecule A molecule in which the electrons are shared equally between the nuclei. As a result, the distribution of charge is even and the force of attraction between different molecules is small. Non-polar molecules show little reactivity.

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