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Lipids
The Structure and Function of Lipids
 Related Resources
• Macromolecules
• Carbohydrates
• Proteins
• Nucleic Acids
• Food Chemistry
 
Lipids are very diverse in both their respective structures and functions. These diverse compounds that make up the lipid family are so grouped because they are insoluble in water. Let's look at some lipid types including fats, phospholipids and steroids.

Fats

Fats are composed of fatty acids and glycerol. Fatty acids consist of a long chain of carbons with a carboxyl group at one end. Depending on their structure, fatty acids can be saturated or unsaturated.

While fats have been denigrated to the point that many believe that fat should be eliminated from the diet, fat serves many useful purposes. Fats store energy, help to insulate the body and cushion and protect organs.

Saturated Fatty Acid
Image credit: Richard Bowen


Phospholipids

While fats are typically composed of three fatty acids, phospholipids have two fatty acids. Phospholipids are a major component of cell membranes.

Phospholipids
Image credit: Steven Berg


Steroids

Steroids have a carbon backbone that consists of four fused ring-like structures. Common examples of steroids include estrogen, testosterone and cholesterol.

Cholesterol
Image credit: Steven Berg


Other Lipids

There are also a number of other lipid types, including prostaglandins, certain types of pigments and waxes.


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