Final answer:
The statement is true; saturated fats contain only single bonds between carbon atoms, while unsaturated fats have one or more carbon-carbon double bonds.
Step-by-step explanation:
The statement that one major difference between saturated fat and unsaturated fat is the number of double bonds or single bonds in the fatty acid side chain and that saturated fats have no double bonds, making the side chains all straight, is true. Saturated fats consist entirely of carbon-carbon single bonds, making them saturated with hydrogen atoms. Conversely, unsaturated fats have one or more double bonds in their carbon chains. Double bonds introduce kinks in the fatty acid chain, preventing tight packing and usually resulting in a liquid state at room temperature. For example, olive oil and other vegetable oils are unsaturated fats, typically liquid at room temperature, while animal fats like butter are often saturated fats, solid at room temperature.