Question

which two groups of macromolecules are used as the primary source of energy for cellular functions? proteins and lipids lipids and carbohydrates nucleic acids and proteins carbohydrates and proteins

Explanation:

Carbohydrates are the main energy - source (e.g., glucose in cellular respiration). Lipids also serve as an energy source, especially when carbohydrates are scarce. Proteins are mainly for building and repair, and nucleic acids store genetic information.

Answer:

B. lipids and carbohydrates