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Introduction to Lipids exam Flashcards

Introduction to Lipids exam
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  • What is the defining characteristic of all lipids?
    They are hydrophobic (do not mix well with water).
  • Triglyceride
    A lipid made of three fatty acids attached to a glycerol molecule; main form of stored energy in adipose tissue.
  • What are the three main types of dietary lipids?
    Triglycerides, phospholipids, and sterols.
  • Phospholipid
    A lipid with two fatty acids and a phosphate group attached to glycerol; forms cell membranes.
  • Sterol
    A lipid with a multi-ring structure; cholesterol is the most common example.
  • What does amphipathic mean?
    Having both hydrophobic (water-fearing) and hydrophilic (water-loving) parts.
  • What is the most abundant lipid in the body and diet?
    Triglycerides.
  • What is the function of triglycerides in the body?
    They store energy in adipose tissue for later use.
  • What is the structure of a fatty acid?
    A hydrocarbon chain with a carboxylic acid (COOH) group at one end.
  • Are the fatty acids in a triglyceride always identical?
    No, they can differ in length and number of double bonds.
  • What is the backbone of a triglyceride molecule?
    Glycerol.
  • What is the main role of phospholipids in cells?
    They form the structure of cell membranes.
  • Why are phospholipids able to form membranes?
    Because they are amphipathic, with hydrophilic heads and hydrophobic tails.
  • Is it necessary to consume phospholipids in the diet?
    No, the body can synthesize them.
  • What dietary component in phospholipids is essential?
    Phosphorus (in the phosphate group).
  • Cholesterol
    A sterol found in animal membranes; regulates membrane fluidity and is a precursor for vitamin D, bile, and hormones.
  • Where is cholesterol found?
    Only in animal-based foods and animal cell membranes.
  • Is cholesterol essential in the diet?
    No, the liver can synthesize all needed cholesterol.
  • What is the function of cholesterol in cell membranes?
    It regulates membrane fluidity and rigidity.
  • What are some compounds synthesized from cholesterol?
    Vitamin D, bile, testosterone, and estrogen.
  • What is LDL and why is it important?
    Low-density lipoprotein; high levels are associated with cardiovascular disease.
  • What is the difference between fats and oils?
    Fats are solid at room temperature; oils are liquid.
  • What does hydrophobic mean?
    Water-fearing; does not mix or dissolve well in water.
  • What does hydrophilic mean?
    Water-loving; dissolves well in water.
  • What are common dietary sources of lipids?
    Butter, oils, fatty meats, fish, dairy, nuts, seeds, and processed foods.
  • What is the general structure of a phospholipid?
    Two fatty acids and a phosphate group attached to glycerol.
  • What is the role of phospholipids in lipoproteins?
    They help form structures like chylomicrons for lipid transport in blood.
  • What is the main function of adipose tissue?
    To store triglycerides for energy.
  • What is the chemical symbol for phosphorus?
    P