Lipids: Properties and Biological Significance PDF

Lipids: Properties and Biological Significance AP Biology  Lesson Outline: — Introduction to Lipids — Properties of Lipids — Biological Significance of Lipids AP Biology  Lipids Greek word “Lipos” which means FAT-LIKE Constitute about 10% of normal...

Lipids: Properties and Biological Significance AP Biology  Lesson Outline: — Introduction to Lipids — Properties of Lipids — Biological Significance of Lipids AP Biology  Lipids Greek word “Lipos” which means FAT-LIKE Constitute about 10% of normal body weight AP Biology  Lipids Third main class of the macronutrients needed in human nutrition. AP Biology  Lipids The lipids are a large and diverse group of naturally occurring organic compounds that are related by their solubility in nonpolar organic solvents (e.g. ether, chloroform, acetone & benzene) and general insolubility in water. AP Biology Lipids — Hydrophobic molecules — Greasy substances — One class of large biological molecules that do not form polymers AP Biology Lipids Structure: —Contains carbon, hydrogen, oxygen and some with phosphorus AP Biology Lipids Structure: —Constructed from two types of smaller molecules: glycerol and fatty acids. AP Biology  Properties of Lipids Insoluble in water but soluble in organic solvents (ether, chloroform, benzene and acetone) Organic Solvents AP Biology  Properties of Lipids Contains CARBON, HYDROGEN and OXYGEN, sometimes contain nitrogen and phosphorus. It is one of the primary building blocks of all Nitrogen is an organic matter on Earth. essential nutrient to produce amino acids, Hydrogen helps proteins, nucleic in producing energy in acids, the body. The main function of phosphorus is in the Most living things use oxygen for cellular formation of bones respiration – the process by and teeth. AP Biology which cells obtain energy.  Properties of Lipids Take part in plant and animal metabolism Plant Metabolism Lipids act as hydrophobic barrier for plant membrane. AP Biology  Properties of Lipids Take part in plant and animal metabolism Plant Metabolism Lipids act as hydrophobic barrier for plant membrane. AP Biology  Properties of Lipids Take part in plant and animal metabolism Plant Metabolism Fatty acid is synthesized from chloroplasts. AP Biology  Properties of Lipids Take part in plant and animal metabolism Plant Metabolism Lipids are stored in the form of chemical energy in seeds for germination. AP Biology  Properties of Lipids Take part in plant and animal metabolism Animal Metabolism Animal fats contain 40 to 50% saturated fatty acids and remain in the solid state (fats). AP Biology  Properties of Lipids Take part in plant and animal metabolism Animal Metabolism The fat deposited in the liver contributes to development of metabolic disorder AP Biology  Properties of Lipids They have less specific gravity than water. The specific gravity of the fats is less than 1 (about 0.86) and, therefore, they float on water surface. AP Biology  Properties of Lipids Fats have definite melting points. The melting point of fat is always higher than the temperature at which it solidifies. AP Biology  Biological Significance of Lipids 1. Lipids forms the three main types of foodstuffs and act as fuel in the body. It yields more heat and energy than carbohydrates. Their caloric value is 9 Kcals/gm. AP Biology AP Biology  Biological Significance of Lipids 2. Deposits of fat underneath the skin exert insulating effect to the body. They protect the body from excessive heat or cold. Fat organisms can withstand heat or cold better than thin ones. AP Biology  Biological Significance of Lipids 3. The mesenteric fat around organs like kidney provides padding and protect the internal organs. AP Biology  Biological Significance of Lipids 4. Building materials. Breakdown products of fats can be utilized for building biologically active materials like cholesterol, which in turn can be utilized for synthesis of certain hormones. AP Biology  Biological Significance of Lipids 4. Building materials. Breakdown products of fats can be utilized for building biologically active materials like cholesterol, which in turn can be utilized for synthesis of certain hormones. AP Biology  Biological Significance of Lipids 5. Some vitamins like A, D, E and K are fat soluble, hence lipid is needed for absorbing these vitamins. AP Biology  Biological Significance of Lipids AP Biology