Types of Fatty Acids
Biology: Cambridge International A Level, topic 2.2.5
Saturated Fatty Acids
A fatty acid is saturated if there are only single bonds between carbon atoms in the hydrocarbon chain.
Structure of saturated fatty acids
- Carbon atoms are NOT joined by double bonds in saturated fatty acids.
- In saturated fatty acids, the number of hydrogen atoms attached to the carbon skeleton is maximised. This means that the fatty acid is saturated.
Function of saturated fatty acids
- Saturated fats are solid at room temperature and usually of animal origin. Saturated fats are linked to an increased risk of cardiovascular disease in humans.
- Examples of foods with a high proportion of saturated fat include cream, cheese, butter, other whole milk dairy products and fatty meats.
Unsaturated fats
When the hydrocarbon chain contains at least one double bond, the fatty acid is unsaturated.
Structure of unsaturated fats
- The main difference between saturated and unsaturated fatty acids is their hydrocarbon tails.
- Unsaturated fatty acids have one or more double bond between carbon atoms in the hydrocarbon chain.
- Cooking oils are examples of unsaturated fatty acids.
Liquid at room temperature
- Double bonds kink the carbon chain so unsaturated fats cannot pack together tightly.
- This explains why they remain liquid at room temperature.
Test yourself on Types of Fatty Acids
What type of bonds are found in saturated fatty acids?
Which of the following is a feature of saturated fats?
What type of fatty acid is shown in this diagram?