Lipids

• Lipid


  a macromolecule made of mostly carbon, hydrogen, and some oxygen with nonpolar C-H bonds, making it hydrophobic

  
• How are lipids efficient energy storage units?

  Due to energy-rich Carbon-Hydrogen bonds
• List a few ways that lipids are crucial to life

  - provides insulation for heat loss

  - forms a protective cushion for organs

  - major component of cell membranes or coatings such as fur, feathers, and leaves
• Triglyceride

  a lipid made of 3 fatty acid molecules and a glycerol

  
• What are triglycerides used for?

  energy storage
• Fatty acid


  hydrocarbon chain with a carboxyl group at one end

  
• Ester linkage


  the bond between glycerol and a carboxyl group from the fatty acid

  
• How are triglycerides formed?

  when the glycerol bonds to 3 fatty acids, also known as an ester linkage, and goes through a dehydration synthesis reaction
• What's the difference between saturated and unsaturated fats?

  saturated fats only have single bonds, while unsaturated fats include double bonds in their hydrocarbon chain

  
• Properties of saturated fats

  solid at room temperature, known to be linked to heart disease

  
• Properties of unsaturated fats

  liquid at room temperature, known to reduce heart disease risks
• Phospholipids


  main component of cell membrane

  
• What are the differences between a phospholipid and a triglyceride?

  triglycerides are fully nonpolar with 3 fatty acids, while phospholipids contain a phosphate group and 2 other fatty acids, making one end polar and one end nonpolar

  
• What is the structure of a phospholipid?

  hydrophilic head and hydrophobic tail
• What do phospholipids form in water?

  lipid bilayer

  
• Lipid bilayer


  a barrier for the cell membrane which allows what can go in or out of the cell
• Steroids

  a lipid made up of 4 carbon-based rings attached to each other, each steroid differs based on the arrangement of atoms in the rings

  
• Cholesterol


  a lipid that is important to cell membranes and a precursor to all other steroids

  
• Testosterone


  a lipid that regulates sexual function, helps build muscle and bone mass

  
• Estrogen


  regulates sexual function, helps in fat storage

  
• Waxes


  made of long carbon-based chains, solid at room temperature, produced in plants and animals
• How do plants use waxes?

  prevents water loss, repels insects
• How do animals use waxes?

  as a form of communication, prevents water loss