(Many months later) Thanks for this comment, I believe you are right! Strangely, there do seem to be many resources that list them as being hydrogen bonds (e.g. Encyclopedia Brittanica: https://www.britannica.com/science/unsaturated-fat which makes me question their editorial process.) In any case, I’ll probably just rephrase to avoid using either term. Thanks again, wish I had seen this earlier!
Well, EB article you linked doesn’t state directly that fatty acids are made out of carbon atoms linked via hydrogen bonds. It has two sentences relevant to the topic, and I am not entirely sure how to parse them:
Unsaturated fat, a fatty acid in which the hydrocarbon molecules have two carbons that share double or triple bond(s) and are therefore not completely saturated with hydrogen atoms. Due to the decreased saturation with hydrogen bonds, the structures are weaker and are, therefore, typically liquid (oil) at room temperature.
The first sentence is (almost) fully correct.
The second sentence, if viewed without the first one, may technically also be correct, but for what I know it’s not and also it’s not what they meant. See, fatty acids are capable of forming actual hydrogen bonds with each other with their “acid” parts (attached the picture from my organic chem course). On the left covalent bonds are shown with solid lines and hydrogen bonds are shown with dashed lines. The “fatty” part of the molecule is hidden under the letter R. On the right there is methyl instead of R (ie it’s vinegar) and hydrogen bonds are not shown—molecules are just oriented in the right way. (I’m really sorry if I’m overexplaining, I just want to make it understandable for people with different backgrounds).
So, if interpreted literally, the second sentence states that unsaturated fatty acids form less hydrogen bonds with each other for whatever reason, and that’s why they are liquid instead off solid. The explanation I’ve heard many times is different, it says that they are liquid because their “fatty” part is bent because double bonds have different geometry, so it is harder for them to form a crystal. I mean, it is still possible that they also form less hydrogen bonds, but I bet it’s insignificant even if true.
But it honestly looks like they don’t mean all of that at all, they are just incorrectly calling covalent bonds between carbon and hydrogen “hydrogen bonds” and they also don’t know what they mean by “the structures are weaker”. It’s still a sin, but not the one you are accusing them of.
I am also completely fine with the phrasing that is currently in the article and I’m sorry for wasting your time with all that overthinking, hope it wasn’t totally useless.
(Many months later) Thanks for this comment, I believe you are right! Strangely, there do seem to be many resources that list them as being hydrogen bonds (e.g. Encyclopedia Brittanica: https://www.britannica.com/science/unsaturated-fat which makes me question their editorial process.) In any case, I’ll probably just rephrase to avoid using either term. Thanks again, wish I had seen this earlier!
Well, EB article you linked doesn’t state directly that fatty acids are made out of carbon atoms linked via hydrogen bonds. It has two sentences relevant to the topic, and I am not entirely sure how to parse them:
The first sentence is (almost) fully correct.
The second sentence, if viewed without the first one, may technically also be correct, but for what I know it’s not and also it’s not what they meant. See, fatty acids are capable of forming actual hydrogen bonds with each other with their “acid” parts (attached the picture from my organic chem course). On the left covalent bonds are shown with solid lines and hydrogen bonds are shown with dashed lines. The “fatty” part of the molecule is hidden under the letter R. On the right there is methyl instead of R (ie it’s vinegar) and hydrogen bonds are not shown—molecules are just oriented in the right way. (I’m really sorry if I’m overexplaining, I just want to make it understandable for people with different backgrounds).
So, if interpreted literally, the second sentence states that unsaturated fatty acids form less hydrogen bonds with each other for whatever reason, and that’s why they are liquid instead off solid. The explanation I’ve heard many times is different, it says that they are liquid because their “fatty” part is bent because double bonds have different geometry, so it is harder for them to form a crystal. I mean, it is still possible that they also form less hydrogen bonds, but I bet it’s insignificant even if true.
But it honestly looks like they don’t mean all of that at all, they are just incorrectly calling covalent bonds between carbon and hydrogen “hydrogen bonds” and they also don’t know what they mean by “the structures are weaker”. It’s still a sin, but not the one you are accusing them of.
I am also completely fine with the phrasing that is currently in the article and I’m sorry for wasting your time with all that overthinking, hope it wasn’t totally useless.