Summary lipids : functions and structures

Lipids Structure and Function


Lipids: Structurally Diverse Class




Some Biological Functions of Lipids
• Storage of energy
• Membrane structure
– Main structure of cell membranes
• Cofactors for enzymes
– Vitamin K: blood clot formation
– Coenzyme Q: ATP synthesis in mitochondria
• Signaling molecules
– Steroid hormones (act body-wide)
– Vitamins A and D (hormone precursors)
• Antioxidants
– Vitamin E

, Classification of Lipids
Two major categories based on the structure and function:

1.Lipids that contain fatty acids (complex lipids)
– can be further separated into:
– storage lipids: triacylglycerols
– membrane lipids: phospholipids, glycolipids
2. Lipids that do not contain fatty acids: cholesterol, vitamins, etc.


Complex Lipids




Fatty Acids
• Carboxylic acids with hydrocarbon chains containing between 4 to 36
carbons

– Almost all natural fatty acids have an even number of carbons.
– Most natural fatty acids are unbranched.
• Saturated: no double bonds between carbons in the chain
• Monounsaturated: one double bond between carbons in the
alkyl chain