Question

multiple choice question
how are lipids best defined?

lipids are biological compounds that are not soluble in water.
lipids are biological compounds that serve as the cells primary energy source.
lipids are biological compounds that catalyze chemical reactions.

Explanation:

• Analyze the first option: Lipids are hydrophobic (not soluble in water) and are a broad group of biological compounds. This matches the definition of lipids.
• Analyze the second option: The cell's primary energy source is glucose (a carbohydrate), not lipids. Lipids are a long - term energy storage molecule.
• Analyze the third option: Molecules that catalyze chemical reactions are enzymes (mostly proteins), not lipids.

Answer:

A. Lipids are biological compounds that are not soluble in water.