Saturated vs unsaturated fats - Structure in relation to room temperature state?

Question

I'm sure most of us have heard that saturated fats are solid at room temperature, and unsaturated fats are liquid at room temperature. I'm wondering how this relates to their chemical structure -- saturated fats contain only single bonds between carbons, yet to qualify as an unsaturated fat a C=C double bond must exist. Since a double bond is stronger than a single bond, and the length of the C=C double bond is shorter than that of the single bond, why is it that the fat containing a double bond is a liquid and saturated fats are solids at room temperature? Seems like the double bond would inhibit movement and the resulting substance would be less like olive oil and more like butter.

Answer 1

You are correct that a double bond is stronger than a single bond but saturated fats tend to form solids because their structure lends itself to forming solids. Saturated fats form long, relatively straight chains whereas unsaturated fats form chains that branch at angles. The best analogy I can come up with is saturated fats are akin to uncooked spaghetti and unsaturated fats are more like cooked noodles that go in all different directions.

You can do a google search for pictures of saturated vs. unsaturated fats in case the spaghetti analogy just doesn't do it for you :)