Lipids

• Triglycerides

  Fats and oils composed of glycerol and three fatty acids. They serve as an energy store, provide thermal insulation, protect internal organs, and act as a source of water during respiration.
• Phospholipids


  Lipids with hydrophobic fatty acid tails and hydrophilic glycerol/phosphate heads. They form the structure of cell membranes, known as phospholipid bilayers.
• Cholesterol


  A lipid molecule with four carbon-based ring structures. It plays a crucial role in regulating membrane fluidity.
• Structure of a Triglyceride

  A triglyceride is formed by combining glycerol with three fatty acids, resulting in the production of a triglyceride molecule and three water molecules.
• Synthesis of Triglycerides

  Triglycerides are synthesized through the formation of ester bonds between fatty acids and glycerol.
• Breakdown of Triglycerides

  Triglycerides are broken down through the hydrolysis of ester bonds, releasing glycerol and fatty acids.
• Properties of Triglycerides

  Triglycerides serve as an energy store, provide thermal insulation, protect internal organs, and act as a source of water during respiration.
• Comparison of Fats and Oils

  Fats and oils can be solid or liquid at room temperature, mainly derived from plants or animals, and can be mainly saturated or unsaturated. High levels of fats and oils can contribute to cardiovascular disease.
• Difference between Stearic Acid and Oleic Acid

  Stearic acid is a saturated fatty acid with no double bonds and more hydrogen atoms. Oleic acid is an unsaturated fatty acid with double bonds present and fewer hydrogen atoms.
• Ester Bond

  An ester bond is a type of bond formed between glycerol and fatty acids in a triglyceride.
• Formation of Ester Bonds

  The formation of ester bonds involves a reaction that joins glycerol and fatty acids, resulting in the release of three water molecules.
• Breakage of Ester Bonds

  The breakage of ester bonds involves a reaction that hydrolyzes the ester bonds in triglycerides.
• Role of Triglycerides in Living Organisms

  Triglycerides serve as an energy store (e.g., adipose tissue), provide thermal insulation, protect internal organs, and act as a source of water during respiration.
• Hydrolysis of Ester Bonds

  Hydrolysis of ester bonds is a process that breaks down triglycerides into glycerol and fatty acids, releasing energy for ATP production.
• Phospholipid Bilayers


  Phospholipid bilayers are membrane structures composed of hydrophobic fatty acid tails and hydrophilic glycerol/phosphate heads. They form the structure of cell membranes.
• Advantage of Unsaturated Fatty Acids in Phospholipid Bilayers

  Unsaturated fatty acids in phospholipid bilayers increase the fluidity and flexibility of the membrane.
• Role of Cholesterol

  Cholesterol plays a crucial role in regulating the fluidity of membranes.
• Structure of Cholesterol

  Cholesterol consists of four carbon-based ring structures.
• Dangers of High Blood Cholesterol

  High blood cholesterol levels can contribute to cardiovascular disease.
• Steroids

  Steroids are lipids derived from cholesterol, including hormones and vitamin D.
• Passage of Steroids into Cells

  Steroids can easily pass through cell membranes.
• Testing for Lipids


  Lipid testing involves a subjective qualitative test known as the emulsion test.