lecture 7_structure functionMacroMol -...

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Lipids = fats
• Formed from C, H and O
– fats , phospholipids , steroids ,
lipoproteins , some vitamins (lipo
soluble)
• 18-25% of body weight
• Hydrophobic
– mostly C-H non-polar bonds (little O
2
)
– insoluble in polar solvents like water
• Combine with proteins Æ lipoproteins
Triglycerides
• Neutral fats Æ single glycerol molecule
and 3 fatty acids
– three-carbon glycerol molecule is the
backbone
• Highly energetic molecules
– 9 calories/gram compared to 4 for
proteins or carbohydrates
– animals store triglycerides in fat cells if
they eat extra food ( why? )
Triglycerides
• One glycerol molecule PLUS fatty acids
• Fatty acids attached by dehydration synthesis
Saturation of Triglycerides
• Determined by the number of single or double
covalent bonds
• Saturated fats contain single bonds Æ