Overview on Fatty Acids

Fatty acids are organic compounds that fall under the category of lipids, which are essential biomacromolecules in the living system. The fatty acid types are saturated, unsaturated, and polyunsaturated fatty acids. Fatty acids play an important role in various physiological processes of the living organism, such as metabolism, formation, and maintenance of cell structure. In this article, we will study the structure, properties, function, and type of fatty acids in detail.

Fatty Acids – Definition and Meaning

Fatty Acids Definition: Fatty acid is an organic biomacromolecule comprising a hydrocarbon chain and a carboxyl group that is a fundamental building block of the living system.

Fatty acids are essential components of various physiological mechanisms of the body. They have varying length that ranges from 4 to 24 carbon atoms, and can have single or double bonds. The hydrocarbon chain of fatty acids ends with a carboxylic acid group. They are the fundamental building blocks of lipid molecules. Fatty acids are responsible for the maintenance and regulation of various cellular functions, synthesis of signalling molecules, hormone regulation, energy storage, inflammatory response, etc.

Fatty Acid

Fatty Acids Formula

Fatty acids are carboxylic acids with a long hydrocarbon chain. Their general formula is CH3(CH2)nCOOH, where n represents the number of carbon atoms in the chain (typically between 12 and 20). This formula indicates a terminal methyl group (CH3), a chain of methylene groups (CH2), and a carboxylic acid group (COOH). The variation in “n” determines the specific type of fatty acid.

Essential Fatty Acids

Essential fatty acids are important types of polyunsaturated fatty aicds that our bodies need to function properly. We can not make them ourselves, so we have to get them from the food we eat. The two categories of essential fatty acid foods include omega-3 and omega-6, which are vital for proper body function.

The omega numbers indicate the position of the first carbon double bond in the fatty acid chain. These fats produce eicosanoids, regulating immune and nervous systems. Omega-3 promotes heart health, while omega-6 increases inflammation and blood pressure. Balancing omega-3 and omega-6 intake in the diet is essential due to their differing effects.

Essential Fatty Acid Foods

Some foods which are high in essential fatty acids are:

Fatty Acids Omega-3

• Fatty fish such as salmon, mackerel, and sardines
• Flaxseeds and chia seeds
• Walnuts
• Soybeans

Fatty Acids Omega-6

• Vegetable oils like
  • corn oil
  • soybean oil
  • sunflower oil
• Nuts such as
  • almonds,
  • sunflower seeds
  • pine nuts
  • walnuts

Properties of Fatty Acids

Some of the common properties of fatty acids are:

• They have varied chain lengths.
• Short-chain fatty acids have around 6 or less carbon atoms, medium-chained fatty acids have between 6 to 12 carbon atoms, and long-chain fatty acids have around 12 or more carbon atoms.
• The degree of saturation depends on the presence and absence of double bonds between the carbon atoms.
• Saturated fatty acids lack double bonds and are solid at room temperature.
• Unsaturated fatty acids have one or more double bonds and are liquid at room temperature.
• Saturated fatty acids require more temperature to melt as compared to unsaturated fatty acids.
• If the fatty acids undergo hydrogenation they may show trans-configuration and are called trans fat.
• In the natural state, the unsaturated fatty acids mostly show cis-configuration.
• Saturated fatty acids are less reactive whereas unsaturated fatty acids are more reactive and can undergo oxidation.

Structure of Fatty Acids

Following are some of the aspects of the structure of fatty acids:

• They are made of hydrocarbon chains and the number of carbon atoms can vary from 4 to 24 atoms making the molecule short or long-chained.
• At one end of the chain, there is one carboxyl group (-COOH) attached.
• When the carbon and hydrogen of the chain are bound to each other by a single bond it forms a straight structure of the saturated fatty acids.
• When the carbon and hydrogen of the chain are bound to each other by double bonds it forms bends in the structure of the unsaturated fatty acids.
• Other than the carboxyl group some fatty acids may have other functional groups like hydroxyl group.

Types of Fatty Acids

Following are some of the different types of fatty acids based on the presence, or absence of double bonds and chain length.

Saturated and Unsaturated Fatty Acids

The key differences between saturated and unsaturated fatty acids are:

Features	Saturated Fatty Acids	Unsaturated Fatty Acids
Structure	Straight with only single bonds	Have bends due to the presence of double bonds
Saturation level	Saturated due to bonds filled by hydrogen atoms.	Unsaturated due to double bonds having empty ends.
Physical State at Room Temperature	Solid	Liquid
Food Sources	Meat, dairy, butter, etc.	Fish oil, avocados, nuts, etc.
Example	Palmitic acid, stearic acid, etc.	Oleic acid, omega-3, and omega-6, etc.

Even Chain and Odd Chain Fatty Acids

The key differences between even-chain and odd-chain fatty acids are:

Features	Even-Chain Fatty Acids	Odd-Chain Fatty Acids
Number of Carbon Atoms	Even number	Odd number
Structure	Straight	Straight
Metabolic Pathway	Beta-oxidation in mitochondria	Beta-oxidation in mitochondria
Found in	Dietary fats, oils, and the body’s adipose tissues	Dietary sources and other fatty acids stored in the body
Example	Palmitic acid, stearic acid, etc.	Pentadecanoic acid, heptadecanoic acid, etc.

Length of Fatty Acids

Fatty acids can be short, medium or long based on the number of carbon atoms present in their structure. The typical length of fatty acids ranges from 4 to 24 carbon atoms.

• If the number of carbon atoms is less than 6 then the fatty acid is a short-chain fatty acid.
• If the number of carbon atoms is between 6 to 12 then the fatty acid is a medium-chain fatty acid.
• If the number of carbon atoms is more than 12 carbon atoms then they are called long-chain fatty acids.
• The main significant difference between the length of chains is that shorter chains are easily absorbed and metabolized by the body whereas longer chains help in maintaining cell structure and in storage of energy.

Circulation of Fatty Acids

Fatty acids after absorption either bind with albumin (a plasma protein) or become a component of lipoprotein like triglyceride to get into the bloodstream. After that some of them are utilized in different physiological processes and the rest get stored in the fatty tissues (adipose tissues). The primary use of fatty acids is for cellular functioning and energy metabolism. When the demand for fatty acids becomes high the adipose tissues release back the stored fatty acids into the bloodstream by the help of a process of lipolysis.

The freed-up fatty acids are then gets transported by the blood to the region of demand where they undergo beta-oxidation to produce energy. By this, the body regulates the demand for fatty acids and maintains homeostasis.

Fatty Acids Examples

Some of the most common examples of fatty acids are:

• Short-chain Fatty Acids

Name	Number of Carbon Atoms	Role/Importance
Acetic acid	2	Helps in cellular metabolism, and lipid synthesis.
Propionic acid	3	Helps in the synthesis of amino acids, and energy generation.
Butyric acid	4	Helps in maintaining gut health, and functioning.

• Medium-chain Fatty Acids

Name	Number of Carbon Atoms	Role/Importance
Caprylic acid	8	Helps in digestion, and has antimicrobial properties.
Capric acid	10	Have therapeutic and antimicrobial properties.
Lauric acid	12	Helps in energy production, and has antimicrobial properties.

• Long-chain Fatty Acids

Name	Number of Carbon Atoms	Role/Importance
Palmitic acid	16	It helps in lipid synthesis and is a major component of cell membrane.
Stearic acid	18	Helps in lipid metabolism, and provides structural support to the cell membrane.
Oleic acid	18	Helps in maintaining the cardiac tissues, and maintains cell membrane integrity.

Functions of Fatty Acids

Some of the common functions of fatty acids are:

• They help in the formation of the phospholipid component of the cell membrane.
• They are the primary site for storage of energy in the form of triglycerides in the adipose tissue of the body.
• They act as the precursor for hormone synthesis.
• They help in the absorption of fat-soluble vitamins like A, D, E, and K.
• The long chain fatty acids like omega-3 help in brain development.
• They get stored in the adipose tissues of the body giving insulation to the internal organs of the body.

Conclusion – Fatty Acids

Fatty acids are one of the important components of the living system. They are organic biomacromolecules that have positive and negative roles in the body of living organisms. They perform various important functions like energy storage, cell membrane synthesis, hormones synthesis, etc. Based on the presence or absence of double bonds and number of carbon atoms present, fatty acids are classified. Understanding some basic concepts on fatty acids can help in better maintenance of the body.

FAQs on Fatty Acid

What are Fatty Acids and Examples?

Fatty acids are biomacromolecules categorized under lipids having a hydrocarbon chain with a carboxyl group. Examples are omega-3, omega-6, palmitic acid, etc.

What is the Function of the Fatty Acids?

The main functions of fatty acids are to maintain and regulate various cellular functions, synthesis of signalling molecules, inflammatory response, etc.

Why is Fatty Acid called Fatty?

Due to their hydrophobic nature and tendency to accumulate in the fatty tissues or adipose tissues are body they are called “fatty”.

What are the Two Main Types of Fatty Acids?

The two main types are fatty acids saturated and unsaturated fatty acids differentiated based on the presence or absence of double bonds in them.

Are Fatty Acids Hydrophilic?

They are not hydrophilic, instead, they are hydrophobic due to their chemical structure.