Final answer:
Fatty acids are building blocks in lipids and have long hydrocarbon chains with a carboxyl group attached. Saturated fatty acids have straight chains, while unsaturated fatty acids have bent chains with double bonds.
Step-by-step explanation:
Fatty acids are building blocks in several other types of lipids. They have a long chain of hydrocarbons to which a carboxyl (carboxylic acid) group is attached. The number of carbons in the fatty acid may range from 4 to 36, with most common ones containing 12-18 carbons. Saturated fatty acids have straight chains, while unsaturated fatty acids have bent chains with double bonds between carbons.