Define saturated compound and ketone. Identify the ketone from the given compounds, explaining your reasoning.

Here are the solutions to your questions:

2.1. A saturated compound is an organic compound that contains only single bonds between carbon atoms. All carbon atoms are bonded to the maximum number of hydrogen atoms possible.

2.2.1. A compound with a carbonyl group bonded to two carbon atoms is a ketone.
Compound E, $\text{CH}_3\text{COCH}_2\text{CH}_2\text{CH}_3$, is pentan-2-one, which is a ketone. The carbonyl carbon is bonded to a methyl group and a propyl group.

$$\boxed{\text{E}}$$

2.2.2. An isomer is a compound with the same molecular formula but a different structural