1.3 Lipids

• Triglycerides are the primary energy storage molecules in the body, providing more than twice the energy per gram compared to carbohydrates or proteins
• What is the role of steroid hormones in the body?

  Chemical messengers
• What are the three main classes of lipids?

  Triglycerides, phospholipids, steroids
• Triglycerides are the primary energy storage lipids, while phospholipids are the structural components of cell membranes
• Triglycerides are joined by ester bonds.

  True
• What structure do phospholipids form in cell membranes?

  Phospholipid bilayers
• Phospholipids are amphipathic, meaning they have both polar and nonpolar regions.

  True
• Lipids are hydrophobic organic compounds that are insoluble in water but soluble in organic solvents
• Triglycerides are the primary energy storage molecules, phospholipids are essential for cell membrane structure
• Arrange the steps in the formation of a phospholipid bilayer in cell membranes:

  1️⃣ Hydrophobic tails face inward

  2️⃣ Polar heads face outward

  3️⃣ Hydrophobic barrier is created

  4️⃣ Substance passage is regulated
• Steroids are hydrophobic and insoluble in water due to their nonpolar nature.


  True
• Triglycerides provide more than twice the energy per gram compared to carbohydrates or proteins
• Phospholipids are the primary structural components of cell membranes.

  True
• Phospholipids are amphipathic, meaning they have both polar and nonpolar regions.


  True
• Lipids are insoluble in water but soluble in organic solvents
• Match the lipid class with its composition and function:

  Triglycerides ↔️ Glycerol + 3 fatty acids, energy storage

  Phospholipids ↔️ Glycerol + 2 fatty acids + phosphate group, structural

  Steroids ↔️ 4-ring structure, signaling
• Triglycerides are formed by joining fatty acids to glycerol through ester bonds
• In cell membranes, phospholipids form a bilayer with hydrophobic tails facing inward
• What does it mean for lipids to be hydrophobic?

  Insoluble in water
• Phospholipids are the main structural components of cell membranes.


  True
• Waxes and fats provide insulation and protection for organisms, helping to maintain body temperature
• Phospholipids contain three fatty acids.

  False
• What are the building blocks of triglycerides?

  Glycerol and 3 fatty acids
• Phospholipids are amphipathic, meaning they have both polar and nonpolar regions
• Phospholipids are composed of a glycerol molecule, a phosphate group, and two fatty acids
• Phospholipid bilayers in cell membranes have hydrophobic tails facing inward and polar heads facing outward.

  True
• Match the lipid function with its description:

  Energy storage ↔️ Triglycerides provide energy

  Structural components ↔️ Phospholipids form cell membranes

  Signaling molecules ↔️ Steroid hormones regulate processes

  Insulation and protection ↔️ Waxes and fats maintain body temperature
• Triglycerides consist of a glycerol molecule with three fatty acids joined by ester bonds.

  True
• Steroids are lipids with a characteristic 4-ring structure
• Phospholipids in cell membranes form a hydrophobic barrier that regulates the passage of substances.

  True
• Lipids provide more energy per gram compared to carbohydrates or proteins
• Triglycerides are the primary energy storage molecules in the body
• Match the lipid type with its primary biological function:

  Phospholipids ↔️ Structural component of cell membranes

  Triglycerides ↔️ Energy storage
• Steroid hormones, which are lipids, act as chemical messengers
• Lipids such as waxes provide insulation and protection for organisms.

  True
• Phospholipids have a hydrophobic tail and a hydrophilic head due to their amphipathic nature.


  True