Catastrophe
Registered Senior Member
"There's something that confuses me about lipids."
Lipids. Generic term for oils, fats, waxes and related products found in living tissues. These are hydrophobic as they have to pack closely together to form membranes.
oils and fats. Oils. An important group of naturally occurring substances consisting of the glycerides of higher fatty acids (eg palmitic acid, stearic acid, oleic acid) which are solid at room temperature (by contrast withn oils which are liquid or semi-solid).
wax Esters of monohydric alcohols of the higher homologues eg beeswax is the myricyl (melissyl) ester of palmitic acid.
phospholipid Any of a group of phosphate-containing lipids, the major structural lipids of most cellular membranes; eg phosphatidyl phospholipids, sphingomyelins.
cholesterolC27H45OH, a sterol of the alicyclic series, found in nerve tissues, gall stones, and in other tissues of the body. One puny -OH with C27H4. Almost completely hydrophobic.
"After looking at the structure of things like cholesterol and phospholipids, something struck me as weird. Naturally lipids are hydrophobic, yet according to its structure it implies that it should be polar."
There is very little polar about an ester or one puny -OH in a large hydrocarbon molecule.
"The presence of its hydroxyl group is the reason for this." No
"Could it be that its overall electronegativity is what's causing lipids to be hydrophobic,No it is there some other aspect I don't understand? Yes
Look at what I wrote above about the contributions of various groups to HLB.
Hope that helps.
Lipids. Generic term for oils, fats, waxes and related products found in living tissues. These are hydrophobic as they have to pack closely together to form membranes.
oils and fats. Oils. An important group of naturally occurring substances consisting of the glycerides of higher fatty acids (eg palmitic acid, stearic acid, oleic acid) which are solid at room temperature (by contrast withn oils which are liquid or semi-solid).
wax Esters of monohydric alcohols of the higher homologues eg beeswax is the myricyl (melissyl) ester of palmitic acid.
phospholipid Any of a group of phosphate-containing lipids, the major structural lipids of most cellular membranes; eg phosphatidyl phospholipids, sphingomyelins.
cholesterolC27H45OH, a sterol of the alicyclic series, found in nerve tissues, gall stones, and in other tissues of the body. One puny -OH with C27H4. Almost completely hydrophobic.
"After looking at the structure of things like cholesterol and phospholipids, something struck me as weird. Naturally lipids are hydrophobic, yet according to its structure it implies that it should be polar."
There is very little polar about an ester or one puny -OH in a large hydrocarbon molecule.
"The presence of its hydroxyl group is the reason for this." No
"Could it be that its overall electronegativity is what's causing lipids to be hydrophobic,No it is there some other aspect I don't understand? Yes
Look at what I wrote above about the contributions of various groups to HLB.
Hope that helps.