Presentation on theme: "Lipids- Does this molecule make me look fat? A.P. Biology Chapter 3 Liberty Senior High School Mr. Knowles."— Presentation transcript:
Lipids- Does this molecule make me look fat? A.P. Biology Chapter 3 Liberty Senior High School Mr. Knowles
Lipids Have C, H, O, but more H and less O than carbohydrates. Four Kinds: Fats, Phospholipids, Terpenes, Steroids Functions of Lipids: 1. May form cell membranes. 2. Used for long- term energy storage.
Types of Fatty Acids Saturated Fatty Acids- single-bonded hydrocarbon chains completely filled with H. Solids at Room Temp. Usually from animals. Ex. Lard Unsaturated Fatty Acids- usually contain a double bond within the hydrocarbon chain, at least one carbon may bond with a H. Liquids at room temp. Derived from plants. Ex. Veg. Oil
Saturated Fatty Acids: -have the maximum number of hydrogen atoms possible. -have no double bonds. (a) Saturated fat and fatty acid Stearic acid Figure 5.12
Unsaturated Fatty Acids: –Have one or more double bonds. (b) Unsaturated fat and fatty acid cis double bond causes bending Oleic acid Figure 5.12
So what is Peanut Butter? If it comes from a plant, it should be a(n)…. Unsaturated Fat! But it’s a solid! It is a hydrogenated fat!
The Importance of Fats Efficient energy-storage molecules because of high # of C-H bonds. More than twice the # in carbos. Convert unused glucose into starch or fats. Fats = 9 kcal/g; Carbo = 4 kcal/g Energy in Saturated fats > Unsaturated fats
So what does this mean for living organisms? The Big Picture! Show the movie! Discovery Channel- Grizzly: Face to Face
The Importance of Lipids for Survival Video: Discovery- Blue Planet: Frozen Seas
2. Phospholipids Substitute a phosphate (PO 4 ) for one fatty acid in a triglyceride. The (PO 4 ) group is polar (charged). The polar ends interact with each other- Hydrophilic The nonpolar (uncharged) hydrocarbon chains interact- Hydrophobic Found in all cell membranes.
Phospholipid structure: –Consists of a hydrophilic “head” and hydrophobic “tails.” CH 2 O P O O O CH CH 2 OO C O C O Phosphate Glycerol (a) Structural formula (b) Space-filling model Fatty acids (c) Phospholipid symbol Hydrophobic tails Hydrophilic head Hydrophobic tails – Hydrophilic head CH 2 Choline + Figure 5.13 N(CH 3 ) 3