ANSC Feeds Practice Exam 2026 - Free Practice Questions and Study Guide

The correct answer focuses on vitamins, which play a crucial role in metabolic processes and immune function. Vitamins are organic compounds that organisms require in small quantities to maintain various biochemical functions. They act as cofactors in enzyme reactions, facilitating metabolic pathways that are essential for energy production and synthesis of biomolecules. For example, several B vitamins are integral to energy metabolism, contributing to the conversion of food into usable energy.

In terms of the immune system, specific vitamins such as A, C, D, and E have been shown to enhance immune function. Vitamin A is important for maintaining the integrity of mucosal surfaces and plays a role in the development of immune cells. Vitamin C functions as an antioxidant and is vital for the growth and repair of tissues, while Vitamin D is critical for regulating the immune response. Vitamin E also serves to protect cells from oxidative stress, supporting overall immune system health.

While carbohydrates, fats, and minerals each have significant roles in nutrition—carbohydrates being primary energy sources, fats providing energy and supporting cell structure, and minerals being essential for various physiological functions—they do not specifically encompass the metabolic and immune functions to the same extent as vitamins. Hence, vitamins are clearly identified as the nutrient class essential for these processes.