What is the primary function of enzymes in the body?

Enzymes play a critical role as biological catalysts in the body, primarily facilitating biochemical reactions, including the digestion of food. Their function in changing certain types of food into soluble forms is essential for nutrient absorption. Through the catalytic action of enzymes, larger macromolecules such as carbohydrates, proteins, and fats are broken down into smaller, more absorbable units—like glucose, amino acids, and fatty acids—during digestion. This process allows the body to utilize the nutrients effectively, making enzymes vital for maintaining metabolic function and energy production.

The other choices highlight functions that are not directly related to the primary role of enzymes. For example, structural support to tissues is provided by proteins like collagen, while the transport of oxygen in the blood is primarily the role of hemoglobin. Storing energy for later use is associated with compounds like glycogen and triglycerides, rather than enzymes themselves. Understanding the specific catalytic role of enzymes clarifies their essential part in facilitating digestion and metabolism.