1. How is the definition of lipid different from protein and carbohydrate?: The
lipid definition is based on the functional definition of being soluble in a non-polar
solvent. Proteins and carbohydrates are based on the structure.
2. What are three functions of lipids?: Any three of: energy, storage, vitamin,
protection, and insulation
3. How does the omega numbering system differ from the simplified nota-
tion?: The simplified notation starts number at the carboxylic acid, while the omega
system starts at the opposite end - from the -CH3.
4. What does unsaturated mean for a fatty acid?: Unsaturated indicates that one
or more double bonds are present.
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, 5. What is the difference between a fat and oil?: An oil is a lipid that is a liquid at
room temperature, while fat is a solid at room temperature.
6. How are phosphoglycerides similar to triacylglycerols? How they different?-
: similar: Both have glycerol as a backbone structure. Both have fatty acids attached
to the glycerol.
Differences: phosphoglycerides have two fatty acids attached to the glycerol and,
as the name implies, triacylglycerols have three fatty acids. Phosphoglyceride has
a polar head group attached.
7. What is the primary function of phosphoglycerides mentioned in this mod-
ule?: forming membrane bilayers
8. Describe at least two functions of sphingolipids.: They serve as blood group
determinants, the structure of membrane bilayers, and in the myelin sheath of
neurons.
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