Saturated fatty acids have no double bonds between carbon atoms, making them saturated with hydrogen atoms. Palmitic acid is a saturated fatty acid with 16 carbon atoms.

The general formula for a saturated fatty acid is $CH_3(CH_2)_{n}COOH$, where n is the number of carbon atoms in the chain.

Monounsaturated fatty acids have one double bond between carbon atoms. Palmitoleic acid is a monounsaturated fatty acid with 16 carbon atoms and one double bond.

The general formula for a monounsaturated fatty acid is $CH_3(CH_2){n-1}CH=CH(CH_2){m}COOH$, where n is the number of carbon atoms in the chain before the double bond, and m is the number of carbon atoms in the chain after the double bond.

Polyunsaturated fatty acids have more than one double bond between carbon atoms. Linoleic acid is a polyunsaturated fatty acid with 18 carbon atoms and two double bonds.

The general formula for a polyunsaturated fatty acid is $CH_3(CH_2){n-6}CH=CHCH_2CH=CH(CH_2){m}COOH$, where n is the number of carbon atoms in the chain before the first double bond, and m is the number of carbon atoms in the chain after the last double bond.

Omega-3 fatty acids have their last double bond three carbon atoms from the methyl end of the molecule. Alpha-linolenic acid is an omega-3 fatty acid with 18 carbon atoms and three double bonds.

The general formula for an omega-3 fatty acid is $CH_3(CH_2){n-3}CH=CHCH_2CH=CH(CH_2){m}COOH$, where n is the number of carbon atoms in the chain before the first double bond, and m is the number of carbon atoms in the chain after the last double bond.

Omega-6 fatty acids have their last double bond six carbon atoms from the methyl end of the molecule. Linoleic acid is an omega-6 fatty acid with 18 carbon atoms and two double bonds.

The general formula for an omega-6 fatty acid is $CH_3(CH_2){n-6}CH=CHCH_2CH=CH(CH_2){m}COOH$, where n is the number of carbon atoms in the chain before the first double bond, and m is the number of carbon atoms in the chain after the last double bond.

Trans fatty acids are formed when unsaturated fatty acids are hydrogenated, a process that converts some of the cis double bonds to trans double bonds. Elaidic acid is a trans fatty acid with 18 carbon atoms and one trans double bond.

The general formula for a trans fatty acid is $CH_3(CH_2){n-1}CH=CH(CH_2){m}COOH$, where n is the number of carbon atoms in the chain before the double bond, and m is the number of carbon atoms in the chain after the double bond. The double bond is in the trans configuration, meaning that the hydrogen atoms on the two carbon atoms involved in the double bond are on opposite sides of the double bond.

Essential fatty acids are fatty acids that cannot be synthesized by the body and must be obtained from the diet. Linoleic acid and alpha-linolenic acid are essential fatty acids.

The two main types of essential fatty acids are omega-3 and omega-6 fatty acids.

Fatty acids have a variety of functions in the body, including energy storage, cell membrane structure, and hormone production.