Final answer:
Saturated fatty acids have no double bonds between carbon atoms, allowing them to have the maximum number of hydrogen atoms, and are typically solid at room temperature. Unsaturated fatty acids, which contain one or more double bonds, are liquid at room temperature.
Step-by-step explanation:
Saturated fatty acids are simple lipid molecules where the chain of carbon atoms is bonded to as many hydrogen atoms as possible, due to the absence of carbon-to-carbon double bonds.
This structure causes these chains to be straight and rigid, which allows them to pack tightly together, often being solid or semi-solid at room temperature; butter and lard are common examples.
In contrast, unsaturated fatty acids, which include monounsaturated and polyunsaturated fatty acids, contain one or more double bonds, introducing kinks in the chain that prevent tight packing and typically remain liquid at room temperature, such as olive oil.
Fatty acids are vital building blocks of fats, oils, and other lipid molecules, excluding steroids.
They serve as crucial structural components and can be found in both plant and animal sources.
The categorization into saturated and unsaturated is based on the presence of single or double bonds between carbon atoms.