q The body
stores lipids as reserve energy.
q Lipids are hydrophobic (“water-hating”) and thus much harder to break down for energy than carbohydrates. Lipids are soluble in other lipids, but NOT in water. q Lipids, however, contain more energy per unit weight then carbohydrates. Thus it is more efficient for the body to use lipids as stored energy. q The body will use its carbohydrate source for initial fuel, but when used up, the body will turn to breaking down lipids for a rich energy source. q Lipids are fat molecules and there are many different kinds. |
FactsFatty acids are important sources of fuel because, when metabolized, they yield large quantities of ATP
- Fatty Acids can be short or long molecules composed of carbon, hydrogen and oxygen. -Saturated fatty acids have single bonds between each carbon of the skeleton, they are "saturated" (full of) hydrogen per carbon. -Unsaturated fatty acids have one or more double bonds between the carbons of the skeleton. This causes the molecule to bend as shown in the figure below. Steroids |
TriglyceridesThey are composed one glycerol and three fatty acids.
They could combine both saturated and unsaturated fatty acids Phospholipids- Phospholipids are major components of cell membranes
- Composed of a head (hydrophilic) and a tail (hydrophobic) Waxes |