Biochemistry Review Chapters: 10, 13, 14, & 15

Biochemistry Review Chapters: 10, 13, 14, & 15
 Chapter 10: Lipids
• Biological Functions of Lipids:
o Storage of energy
â–ª Reduced compounds: lots of available energy
â–ª Hydrophobic nature: good packing
o Insulation from environment
â–ª Low thermal conductivity
â–ª High heat capacity (can “absorb” heat)
â–ª Mechanical protection (can absorb shocks)
o Water repellant
â–ª Hydrophobic nature: keeps surface of the organism dry
• Prevents excessive wetting (birds)
• Prevents loss of water via evaporation
o Buoyancy control and acoustics in marine mammals
â–ª Increased density while diving deep helps sinking (just a hypothesis)
â–ª Spermaceti organ may focus sound energy: sound stun gun?
• More functions:
o Membrane structure
â–ª Main structure of cell membranes
o Cofactors for enzymes
â–ª Vitamin K: blood clot formation
â–ª Coenzyme Q: ATP synthesis in mitochondria
o Signaling molecules
â–ª Paracrine hormones (act locally)
â–ª Steroid hormones (act body-wide)
â–ª Growth factors
â–ª Vitamins A and D (hormone precursors)
o Pigments
â–ª Color of tomatoes, carrots, pumpkins, some birds
• Depending on wave lengths is what gives off color
o Antioxidants
â–ª Vitamin E
• Classification of lipids:
o Based on the structure and function
â–ª Lipids that do not contain fatty acids: cholesterol, terpenes,…
â–ª Lipids that contain fatty acids (complex lipids)
• Can be further separated into
o Storage lipids and membrane lipids