Lipids Flashcards
What are storage lipids used for?
Energy storage and insulation.
What are triglycerides composed of?
Three fatty acids esterified to one glycerol.
What are fatty acids?
Carboxylic acids with long hydrocarbon chains.
What are saturated vs unsaturated fatty acids?
Saturated: no double bonds; Unsaturated: one or more double bonds.
How are omega-3 and omega-6 fatty acids defined?
By the position of the double bond from the methyl end.
Why are omega-3 fatty acids important?
They are essential for health but must be obtained from diet.
What influences fatty acid solubility?
Chain length and number of double bonds.
What influences the melting point of fatty acids?
More double bonds = lower melting point due to less packing.
What is partial hydrogenation?
Adds hydrogen to unsaturated fats, sometimes forming trans fats.
What are waxes made of?
Long-chain fatty acids esterified to long-chain alcohols.
What are the main types of structural lipids?
Glycerophospholipids, sphingolipids, galactolipids, sterols, ether lipids.
What is the structure of glycerophospholipids?
Two fatty acids + glycerol + phosphate + polar head group.
What are galactolipids and where are they found?
Chloroplast membranes in plants; most abundant membrane lipid in biosphere.
What is a sphingolipid?
Lipids with a sphingosine backbone and variable head groups.
What is a sphingomyelin?
A sphingolipid with phosphocholine head; in neuron membranes.
What are glycosphingolipids?
Sphingolipids with sugar heads like cerebrosides.
What are gangliosides?
Complex glycosphingolipids with oligosaccharides and sialic acid.
What roles do sphingolipids play in the body?
Neural membranes, immune recognition, and blood group markers.
What is cholesterol’s function in the membrane?
Regulates membrane integrity, fluidity, and protein anchoring.
What molecules are synthesized from cholesterol?
Steroid hormones and bile acids.
What is PIP2 and its function?
A membrane lipid that is a precursor to second messengers like IP3.
What are eicosanoids derived from?
Arachidonic acid.
What are the roles of prostaglandins?
Inflammation, fever, smooth muscle contraction.
What are thromboxanes and their functions?
Promote blood clotting and reduce blood flow.
