Lipids - Macromolecules PDF

LIPIDS  Lipids ▪ This are organic molecule came from the Greek word “lipos” which means “fat”. These are the substances that include fats and fat-like substances such as phospholipids, waxes, steroids, and others. It is mainly consists of carbon, hydrogen, and oxyge...

LIPIDS  Lipids ▪ This are organic molecule came from the Greek word “lipos” which means “fat”. These are the substances that include fats and fat-like substances such as phospholipids, waxes, steroids, and others. It is mainly consists of carbon, hydrogen, and oxygen. ▪ Lipids are classified as hydrophobic. General characteristics of lipids: Lipids are relatively insoluble in water. Lipids have high energy content and are metabolized to release calories. Pure fats are colorless, they have extremely bland taste.  Functions: ▪ For energy storage ▪ Regulating and signaling ▪ For protection and insulation  Classification of Lipids 1. Fats (triglycerides) 2. Phospholipids 3. Steroids  Fats (triglycerides) Function for long-term energy storage. They contain three fatty acids attached to each glycerol molecule, fat, and oil. They are immiscible with water.  Types of Fatty Acids Saturated are solid at room temperature and mostly found in animals. There no double bonds in its structure. Examples are tropical oils such as coconut and palm oil, lard, butter and dairy products.  Types of Fatty Acids Unsaturated occur in liquid state at room temperature and mostly found in plants. It is believed to be healthier than saturated fats. Examples are oils from nuts and seeds, vegetable oil, olive oil, avocado oil and fish oil.  Types of Fatty Acids Trans Fat is a type of unsaturated fat on which they are made artificially in a process called “hydrogenation” by adding hydrogen to liquid oils in order to make them solid. Baked goods, microwave popcorn, refrigerated dough, fried foods, including french fries, doughnuts and fried chicken, nondairy coffee creamer and stick margarine  Phospholipids Are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain fatty acid molecules and one phosphate group. They are responsible for the polar and nonpolar characteristics of cell membrane. The head is hydrophilic (attracted to water) while the hydrophobic tails repel to water.  Steroids Are lipids with a carbon skeleton of four fused rings. Includes cholesterol, sex hormones estradiol and testosterone, drugs used in anti-inflammatory medicine dexamethasone, and other steroids found in plants, animals, and fungi.  Steroids 1. Cholesterol - most abundant steroid - distributed in all cells and serves as major membrane component 2. Bile Salts ⁻ aid in digestion of fats 3. Ergosterol ⁻ yeast steroid ⁻ converted to Vitamin D.  Steroids 4. Glycosides - Potent heart drugs 5. Adrenal Cortex Hormones - involves in metabolism 6. Sex Hormones - controls sexual characteristics and reproduction