Lipids A Family of Hydrophobic Macromolecules Lipid Facts

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 • .

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

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

Function 1. . 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_Sk elett. 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

• 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 –. –. –.

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

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_memb rane_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: Progestero ne-2 D-skeletal. png TESTOSTERONE Source: http: //en. wikipedia. org/wiki/Image: Testosteron e_structure. png

Steroids made from Cholesterol Source: http: //upload. wikimedia. org/wikipedia/en/b/b 0/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 Glycerides Phospholipids Steroids Function Structure