Terms in this set (21)
What do all lipids have in common?
All lipids are nonpolar and hydrophobic, thus all lipids are insoluble in water and are linked by nonpolar covalent bonds.
What elements make up lipids?
carbon, hydrogen, and oxygen
What are the four major groups of lipids?
fats or triglycerides
functions of fats
long term energy storage, insulation- blubber, body cushioning
What two molecules are lipids made from?
glycerol and fatty acids
structure of glycerol
three carbon chain molecule with each carbon containing a hydroxyl group and all the other open bonds containing hydrogen
a chain of carbon with hydrogens attached
What type of bond forms between carbon & hydrogen?
nonpolar because carbon and hydrogen have equal electronegativity and are thus hydrophobic
structure of a fatty acid
a hydrocarbon chain with about 15 carbons with a carboxyl group attached at one end
In order to make a fat what must combine together?
three fatty acids must link to one glycerol molecule to make a fat. fatty acids link to glycerol in the process of dehydration synthesis between all three hydroxyl groups of glycerol and the carboxyl group of each fatty acid
a fatty acid with no double bond is called
a fatty acid with one or more double bonds is called
characteristics of unsaturated fatty acids
unsaturated fatty acids have less than the maximum number of hydrogens, so the double bonds within carbon chain kinks/bends in the chain, thus preventing the fatty acids from packing tightly together- this means they are a liquid at room temperature
they come from plants
liquid at room temp
ex- vegetable oil
characteristics of saturated fatty acids
they contain the maximum number of hydrogen atoms, so there are no kinks/bends that prevent the fatty acids from packing together, so they are solid at room temperature.
comes from animals
unhealthy- contribute to heart disease and cancer
ex- butter, lard
What is the difference between mono and polyunsaturated?
monounsaturated means only one double bond between carbons- healthiest, and polyunsaturated has more than one double bond between carbons
major component of cell membranes
-two fatty acids linked to a glycerol molecule, and a phosphate group attached to the third hydroxyl group of glycerol.
-schizophrenic because the phosphate functional group is polar and the fatty acids are nonpolar
-the head is a polar hydrophilic phosphate group
-the tail is two nonpolar hydrophobic fatty acids
-lipids whose carbon skeleton is bent to form four fused rings, they have three six sided rings and one five sided ring
-cholesterol is the template for all steroids
Is cholesterol a component of animal cell membranes? Plant cell membranes?
animal cell membranes, not plant cell membranes
What type of hormone is made from steroid lipids?
What is the most hydrophobic lipid and serves as a waxy coat to prevent drying out?
waxes are the most hydrophobic