Lipids encompass which four of the following groups of compounds?

• A. Polysaccharides, glycoproteins, glycolipids, and nucleic acids
• B. Amino acids, nucleotides, monosaccharides, and disaccharides
• C. Enzymes, vitamins, minerals, and hormones
• D. Fatty acids, triacylglycerols, phospholipids, and sterols

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the definition of lipids. Lipids are a diverse group of hydrophobic or amphipathic molecules that are insoluble in water but soluble in organic solvents. They play key roles in energy storage, membrane structure, and signaling.
2. Step 2: Review the major classes of lipids. Lipids are broadly categorized into fatty acids, triacylglycerols, phospholipids, and sterols. Each of these groups has distinct structural and functional characteristics.
3. Step 3: Compare the options provided in the question. Eliminate groups that do not fit the definition of lipids. For example, polysaccharides, glycoproteins, and nucleic acids are not lipids; they belong to other macromolecule categories such as carbohydrates and nucleic acids.
4. Step 4: Focus on the correct answer: fatty acids, triacylglycerols, phospholipids, and sterols. Fatty acids are the building blocks of many lipids, triacylglycerols are storage lipids, phospholipids are key components of cell membranes, and sterols (like cholesterol) are involved in membrane fluidity and signaling.
5. Step 5: Summarize the reasoning. Lipids are defined by their hydrophobic nature and include fatty acids, triacylglycerols, phospholipids, and sterols. These groups are distinct from other macromolecules like proteins, carbohydrates, and nucleic acids.