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LIPIDS. Families of lipids include fats, phospholipids, and steroids; made up mostly of hydrocarbons. These families above DO NOT mix with water. LIPIDS. Major function is for energy and nutrient storage ( A gram of fat stores more than twice as much energy as a gram of a polysaccharide.)
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LIPIDS • Families of lipids include fats, phospholipids, and steroids; made up mostly of hydrocarbons. • These families above DO NOT mix with water
LIPIDS • Major function is for energy and nutrient storage (A gram of fat stores more than twice as much energy as a gram of a polysaccharide.) • Insulation, protect internal organs, hormones, used to make up cell membrane • Fat molecules are made up of four parts: • a molecule of glycerol (on the right) and • three molecules of fatty acids. • This structure forms a triglyceride. • Glycerol is a 3 carbon alcohol • Fatty Acids have LONG carbon skeletons that range in length
Fatty acids • A hydrocarbon chain with an acidic –COOH group at one end that attaches to the glycerol molecule. • Since the other unattached end of the fatty acid is –CH, it is a non-polar molecule and will not attract polar molecules such as water hydrophobic
Saturated FATS • Have the maximum number of the hydrogen atoms at each carbon (no double bonds); as many hydrogens as possible bonded to the carbon skeleton • Most fats present in animals ie. Cows, sheep • Solid at room temp. • It contributes to cardiovascular disease since their structure is “saturated”
Unsaturated FATS • Have one or more DOUBLE BONDS; has one or more double bonds and will have a kink in its tail wherever there is a double bond. • Examples: Plant fats • Liquid at room temp. • Fat from plants and fishes are generally unsaturated and are liquid at room temperature – they are oils. Double Bond
Phospholipids • Phospholipids are similar to fats, but they only have two fatty acids tails. • The 3rd carbon is attached to a phosphate group (water loving) • When phospholipids are added to water, they self assemble • into micelles: a phospholipid droplet with the hydrophobic • tails inside and the hydrophilic heads facing the water. • Heads are hydrophillic (water loving) • Tails are hydrophobic (water hating) • Cell membrane is made of 2 layers of phospholipids
Steroids • Made of a CARBON skeleton of 4 fused rings • Cholesterol is an important steroid for the body, in animal cell membranes • It is the precursor for the production of other steroids and hormones
Steroids • BUT a high concentration of cholesterols causes ARTHEROSCLEROSIS which can eventually lead to heart attacks!! Oh No!