The correct answer is option 1 - All proteins are enzymes. This statement is not correct because not all proteins are enzymes. Proteins are large, complex molecules composed of chains of amino acids, while enzymes are a specific type of protein that act as catalysts in biochemical reactions. While enzymes are proteins, not all proteins have enzymatic activity.

Option 2 - Mostly enzymes are proteins is a correct statement. Enzymes are indeed mostly proteins, although there are some exceptions such as ribozymes, which are RNA molecules with catalytic activity.

Option 3 - All fats are energy-rich compounds is a correct statement. Fats, also known as lipids, are macronutrients that provide a concentrated source of energy, with each gram of fat providing 9 calories.

Option 4 - Glucose is a common carbohydrate is also a correct statement. Glucose is a monosaccharide and is one of the most important carbohydrates in biological systems. It is used as a primary source of energy in cells and is a building block for larger carbohydrates like glycogen and starch.

Alert - correct answer should be: None of the statements are incorrect.