Lipids Biochem Lab

• Lipids are insoluble in water but soluble in organic solvents
• Lipids include triglycerides, phospholipids, and steroids
• Triglycerides consist of glycerol and three fatty acids
• Steroids are lipid molecules with four fused carbon rings
• Phospholipids have two fatty acid chains attached to the glycerol backbone and one phosphate group
• Cholesterol is an example of a steroid found in animal cells
• Lipids is the only biomolecule that is not a biopolymer
• Triglycerides transport and store energy
• Steroid hormones send messages in cells
• Bile salts from cholesterol help digest fat
• Fatty acids metabolize to create energy
• Phospholipids and cholesterol make biological membranes
• Phospholipids are the gatekeepers that let some molecules into the cells, but require others to come in with proteins
• The 3 types of membrane lipids are phospholipids, glycolipids and archaebacterial ether lipids
• What is the name of this lipid?

  Sphingolipid

  
• What is the name of this lipid?

  Glycerophospholipids

  
• Sphingomyelin is what kind of lipid?

  Sphingolipid
• Glycolipids, a large group of sphingolipids, are so called because they contain one or more molecules of sugar
• This type of lipid is a glycerophospholipid

  
• This type of lipids is an Archaebacterial ether lipids

  
• This type of lipids is a sphingolipid

  
• This type of lipid is a galactolipids or sulfolipids

  
• This type of lipid is a sphingolipid

  
• Oils are fatty acids that are liquid at room temperatures
• Fats are fatty acids that are solid at room temperature
• Oils may either be saturated or unsaturated
• The solubility test evaluates lipid solubility in various solvents
• The reagents for the solubility test are chloroform, acetone, cold ethanol and hexane
• A positive indication of soluble layer will be observed in the solubility test
• Grease spot test identifies lipids by liquids through translucent spots in filter paper
• A positive indication is found in the Grease-spot test when there is a translucent spot in the filter paper
• Grease spot test uses heat to test for lipids and fats.
• Saponification test determines if an unknown substance contains fatty acid esters or triglycerides.
• In saponification test, sodium hydroxide (NaOH) is added to the sample to determine whether it produces soap.
• Concentrated Sulfuric acid, solid sodium chloride, and 3M sodium hydroxide are the reagents used for the saponification test
• If the solution turns cloudy, it indicates that the sample contains fatty acids.
• The grease spot reagents include DCM, cholesterol, and lecithin (0.1 g/mL of DCM)
• A positive test is involved in the solubility test if the substance dissolves in a solvent
• The reagents contained in the huble's reagent is the alcoholic solution of iodine with mercuric chloride
• The violet color of iodine becomes colorless if the oil or fat is unsaturated