Which one of the following statements is NOT coiTect ?

The statement 'All proteins are enzymes' is incorrect because while enzymes are a specialized category of proteins, not all proteins function as catalysts [2]. Proteins serve diverse roles, including structural support (e.g., keratin), transport (e.g., hemoglobin), and hormonal regulation [1]. Conversely, most enzymes are proteins, but exceptions exist; ribozymes are RNA-based molecules that perform catalytic functions without being proteins [2]. Regarding the other options, fats are indeed energy-rich compounds that provide significant metabolic fuel. Glucose is the most abundant and common monosaccharide carbohydrate, serving as a primary energy source for cells. Therefore, while the majority of enzymes are proteins, the inverse—that all proteins are enzymes—is biologically false [2].

Sources

1. [2] https://www.sciencedirect.com/topics/medicine-and-dentistry/carbohydrates
2. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.3 > p. 86