A Family of Hydrophobic Macromolecules Lipids A Family of Hydrophobic Macromolecules

Lipid Facts Fat: Oil: Contribute 30-50% of calories for Americans . Lipids are primarily consumed for energy Diverse groups:

Lipid Facts Continued .

Types of Lipids 4 major sub-groups: 1) Glycerides (fats) 2) Phospholipids 3) Steroids 4) Waxes

Lipids Attached to… Lipid + Carbohydrate = (cell signalling and attaching) Lipid + Phosphate = (cell membranes) Lipid + Protein = (cell signalling, structure, attaching)

Function . 2. . 3. .

4. Structural: 5. Vitamins and Hormones 6. Waxes:

Glycerides (Fats) . Glycerides are defined by their fatty acid components: Number (1 to 3 fatty acid) Length Degree of saturation (referring to if double bonds between carbons are present or not)

Glycerol . GLYCEROL Source: http://en.wikipedia.org/wiki/Image:Glycerin_Skelett.svg

Fatty Acids . Usually hydrophobic (can be amphipathic)

Naming Glycerides Monglycerides = 1 fatty acid Diglycerides = 2 fatty acids Triglycerides = 3 fatty acids

Fatty Acid Nomenclature Based on: Number of carbons Number of double bonds Oleic Acid

Saturated . Implicated in coronary heart disease (CHD) Meats, dairy Unsaturated Less stable to off flavor development Vegetables, legumes, fish

Linolenic Acid, an Omega 3 Fatty Acid Polyunsaturated:  Highly Unsaturated:  Omega 3 Fatty Acids Good for reducing CHD High in fish Linolenic Acid, an Omega 3 Fatty Acid

Unsaturated Fatty Acids . Trans double bonds Cis double bonds

Unsaturated: double bonds between 1 or more carbons Saturated: only single bonds

Formation of a triglyceride

Phospholipids . Cell membrane Amphipathic: Phosphate head = hydrophillic Fatty acid tails = hydrophobic Source: http://en.wikipedia.org/wiki/Image:Phospholipid.svg

Form micelles, liposomes or bilayers in water Cell membranes (selectively permeable) are composed of bilayers of phospholipids. Source: http://en.wikipedia.org/wiki/Image:Cell_membrane_detailed_diagram.svg

LIPIDS

Steroids . Also a membrane component CHOLESTEROL Source: http://en.wikipedia.org/wiki/Image:Cholesterol.svg PROGESTERONE Source: http://en.wikipedia.org/wiki/Image:Progesterone-2D-skeletal.png TESTOSTERONE Source: http://en.wikipedia.org/wiki/Image:Testosterone_structure.png

Steroids made from Cholesterol Source: http://upload.wikimedia.org/wikipedia/en/b/b0/Steroidfromcholesterol.PNG

Cholesterol Why is cholesterol important in the body? . Foods high in cholesterol Organ meats Eggs Shellfish

CONNECTION Anabolic steroids pose health risks Anabolic steroids are natural and synthetic variants of the male hormone testosterone Build up bone and muscle mass Can cause serious health problems

(4 ring compounds)

Waxes Extremely hydrophobic Cutin: cuticle of leaf

Function and Structure of Lipids Lipid Molecule Function Structure Glycerides Phospholipids Steroids