Lipids

• What are the three general types of organic compounds organisms rely on for energy?

  Carbohydrates, amino acids, and lipids
• Why are lipids commonly referred to as fats?

  They are composed mostly of carbon-hydrogen bonds
• What is the primary source of fuel for the body?

  Lipids
• How do lipids contribute to cell membranes?

  They provide stability and allow transmembrane transport
• What special mechanism do lipids require for circulation in the blood?

  Special transport mechanism
• What are the classes of lipids?

  • Fatty Acids
  • Triglycerides
  • Phospholipids
  • Cholesterol
  • Glycolipids
• What are the two major functions of fatty acids?

  Building blocks for triglycerides and energy sources
• What are the classifications of fatty acids based on chain size?

  Short, medium, and long chain
• What characterizes dietary fatty acids?

  They are straight chain compounds with even carbons
• What distinguishes saturated fatty acids from unsaturated fatty acids?

  Saturated have no double bonds; unsaturated have double bonds
• What is the effect of double bonds on unsaturated fatty acids at room temperature?

  They make unsaturated fatty acids more liquid
• What are free fatty acids primarily bound to in the blood?

  Albumin
• What is the composition of triglycerides?

  Glycerol and three fatty acids
• What is the main constituent of stored body fat in humans?

  Triglycerides
• What type of lipid is most abundant and derived from phosphatidic acid?

  Phospholipids
• What is the role of phospholipids in cellular metabolism?

  They participate in metabolism and blood coagulation
• What is the second most abundant lipid in the body?

  Cholesterol
• Where is cholesterol synthesized in the body?

  In the liver
• What is the recommended daily intake of cholesterol for most adults?

  Less than 300 mg
• What percentage of cholesterol is mobile in the body?

  30%
• What are the two types of cholesterol based on their structure?

  Free cholesterol and esterified cholesterol
• What is the simplest form of glycolipids?

  Cerebroside
• What is the role of apolipoproteins in the body?

  They regulate plasma lipid metabolism
• What is Apo A primarily associated with?

  HDL
• What is the primary purpose of lipoproteins?

  To transport cholesterol, triglycerides, and phospholipids
• What are the major types of lipoproteins?

  1. Chylomicrons
  2. Very-Low Density Lipoprotein (VLDL)
  3. Low-Density Lipoprotein (LDL)
  4. High-Density Lipoprotein (HDL)
• What is the density range of chylomicrons?

  Less than 0.93 g/mL
• What is the diameter range of HDL?

  • 5-12 nm
• What is the triglyceride content percentage in chylomicrons?

  84% by weight
• What indicates the presence of chylomicrons in a fasting serum specimen?

  A creamy layer rising to the top
• What are the characteristics of major human lipoproteins?

  • Chylomicrons: Density <0.93 g/mL, Diameter 80-1200 nm
  • VLDL: Density 0.93-1.006 g/mL, Diameter 30-80 nm
  • LDL: Density 1.019-1.063 g/mL, Diameter 18-30 nm
  • HDL: Density 1.063-1.21 g/mL, Diameter 5-12 nm
• What is the main function of chylomicrons?

  Transport dietary triglycerides and cholesterol
• What is the content percentage of triglycerides in chylomicrons?

  90-95%
• What happens to chylomicrons after they transport triglycerides?

  They deposit chylomicron remnants in the liver
• What is the significance of the creamy layer in serum specimens?

  It indicates a defect in chylomicron clearance
• What is the primary component of chylomicrons?

  Triglycerides
• What is the role of apolipoproteins in lipoproteins?

  They maintain structural integrity and function
• What is the function of Apo B-100?

  It binds to LDL cell receptors
• What is the role of Apo E?

  It targets chylomicrons and VLDL remnants
• What is the primary purpose of lipoproteins in the body?

  To transport lipids in the bloodstream