Lipids Flashcards
Lipids are synthesized from _______.
Acetyl CoA
How are lipids used for structural support?
Mechanical and electrical insulation; serve as anchors that tethers proteins to membranes
How are lipids used for signaling events?
Cofactors; signaling molecules during development; immune response, vision, etc.
How do lipids provide mechanical protection and thermal insulation?
Adipose tissue
What are the two broad classes of lipids?
fatty acid derivatives and isprenoids
What is a lipid?
water insoluble bio molecule that is highly soluble in organic solvents: hydrophobic properties are due to fatty acids
Describe fatty acid derivatives
Monocarboxylic acid with a long hydrocarbon chain
What are examples of fatty acid derivatives?
glycerides, membrane lipids, and eicosanoids
What does the inefficient expression of lipase lead to?
gastrointestinal problems
Where are fatty acids oxidized?
mitochondria to generate ATP
What are two examples of saturated fatty acid derivatives?
palmitic acid and Stearic acid
What are 3 examples of unsaturated fatty acid derivatives?
Oleic acid
Linoleic acid
and arachidonic acid
What can supplement for lipase when not available?
Bile salts
isoprenoids contain multiple units of a five carbon molecule, called isoprene.
What are two examples of isoprenoids?
Cholesterol and bile salts
describe ω-3 and ω-6 fatty acids
Omega-3 fatty acids are essential fatty acids whose final double bonds are located 3 carbons from the end of their hydrocarbon tails. Linolenic acid is common
Omega-6 have last double bond 6 carbons from the end of hydrocarbon tails; linoleic acid and arachidonic acid
What are components of lung surfactant? What is the function?
Phosphatidylcholine (lecithin), sphingomyelin, and phosphatidylglycerol
serves as a lubricant that lowers the surface tension of alveoli, making it easier for the lung to expand
What causes respiratory distress syndrome
Immature lungs of preterm infant often fail to produce surfactant and leads to RDS, impairing gas exchange and increasing risk of partial lung collapse.
*Test measures lecithin to sphingomyelin ratio in amniotic fluid allows for the maturity of a fetus’s lungs to be determined. Ratio less than 2:1 indicates deficiency and possible RDS. Ratio greater means mature lungs
What causes gallstones?
Gallbladder stores bile, a lipid-emulsifying liquid. Cholesterol normally found in bile needs bile salts to stay in solution. Too much cholesterol and too little bile salts = cholesterol hardens into pebble solids.
What can the continued disturbance of bile salt metabolism lead to?
malabsorption syndromes such as steatorrhea and extreme cases, deficiency in fat-soluble vitamins.
*Oral chenodeoxycholic acid used to replace bile acid pool and can help dissolve stones
