7.4 Lipids Flashcards
What are the three physiological roles of lipids?
- in cellular membranes phospholipids are a barrier between intra and extracellular environments
- in adipose tissue triglycerides store energy
- cholesterol is a special lipid that serves as a precursor to steroid hormones
What are saturated and unsaturated fatty acids?
saturated = no double bonds
unsaturated = double bonds
What is the basic structure of a fatty acid?
long chain unsubstituted alkane ending in a carboxylic acid
What is a micelle?
structure formed by free fatty acids in an aqueous solution
What is the driving force for micelle and lipid bilayer formation?
hydrophobic interaction
What are soaps?
sodium salts of fatty acids
What does it mean to be amphipathic?
both hydrophobic and hydrophilic
What are triacylglycerides?
three fatty acids esterified to a glycerol molecule
What is saponification?
process of producing soap through a base-catalyzed hydrolysis of triglycerides from animal fat into fatty acid salts
What are lipases?
enzymes that hydrolyze fat
Why are fats more efficient at energy storage than carbohydrates?
packing
energy content
What are phospholipids?
membrane lipids derived from diacylglycerol phosphate
What are detergents?
substance that efficiently solubilize oils while remaining highly water soluble
What are the structural determinants of membrane fluidity?
- degree of saturation
- tail length
- amount of cholesterol
What is terpene?
broad class of compounds built from isoprene units with a general formula (C5H8)n
