Fatty Acids
Fatty Acids
Building Blocks
- Fatty acids serve as the fundamental building blocks for other lipids.
Structure of a Fatty Acid
A fatty acid consists of:
- A carboxyl group (-COOH) at one end (the head).
- A long chain of carbons (the tail) at the other end.
The carbon chain is unbranched, forming a straight line.
The number of carbons in the chain varies, typically ranging from 12 to 20 in naturally occurring fatty acids.
The number of carbons is always even because fatty acid chains are built by adding two carbons at a time.
Types of Fatty Acids
- Fatty acids are classified as either saturated or unsaturated.
Saturated Fatty Acids
Saturated fatty acids have the maximum number of hydrogen atoms attached to each carbon atom.
They are commonly found in animal fats.
Due to their straight, unkinked structure, saturated fatty acids can pack together tightly.
As a result, they are solid at room temperature (e.g., Crisco, butter).
Unsaturated Fatty Acids
Unsaturated fatty acids do not have the maximum number of hydrogen atoms due to the presence of at least one double bond between carbon atoms.
The double bond creates a kink in the fatty acid chain.
These kinks prevent unsaturated fatty acids from packing together tightly.
Consequently, they are liquid at room temperature (e.g., canola oil, olive oil).
These are typically plant fats.
Trans Fats
Normal unsaturated fats have a cis bond, which creates a significant kink in the fatty acid structure due to both hydrogen atoms being on the same side.
Trans fats have a trans bond, where hydrogen atoms are on opposite sides, reducing the kink.
Trans fats behave more like saturated fats and are solid at room temperature.
Most trans fats are created in a lab, although some occur naturally.
Trans fats are considered unhealthy because the body has difficulty processing them due to their infrequent natural occurrence.
The body has few enzymes to deal with trans fats, leading to efforts to eliminate them from diets.