Which best defines the term nutrient?
A Compound that is absorbed from intestines
B Ingested compound that alters appetite and/or hunger
C Ingested compound used for growth, repair or maintenance
D Compound that stimulates a change in target cell function
The correct answer and explanation is:
Correct Answer: C. Ingested compound used for growth, repair or maintenance
Explanation:
A nutrient is a chemical substance that an organism must obtain from its environment or diet to sustain life. These substances are crucial for various biological processes, especially growth, repair of body tissues, and maintenance of bodily functions.
Nutrients can be macronutrients—which include carbohydrates, proteins, and fats—and micronutrients, like vitamins and minerals. Water is also considered a vital nutrient. All these are either metabolized for energy or used as building blocks for cells and tissues.
Let’s examine the other choices:
- A. Compound that is absorbed from intestines
This is only partly correct. While nutrients are absorbed from the intestines, not everything absorbed there qualifies as a nutrient. Some absorbed substances (e.g., toxins or medications) are not nutrients because they don’t contribute to growth, repair, or maintenance. - B. Ingested compound that alters appetite and/or hunger
This describes substances like appetite suppressants or stimulants, not nutrients. Nutrients do not primarily serve to alter appetite or hunger; rather, they serve physiological needs. - D. Compound that stimulates a change in target cell function
This sounds like a hormone or a signaling molecule, not a nutrient. While some nutrients (like calcium or glucose) can have signaling roles, that is not their defining feature.
Therefore, C is the most accurate and comprehensive definition of a nutrient because it reflects the primary purpose nutrients serve in biological systems: supporting life processes through growth, repair, and maintenance.
Understanding nutrients is fundamental in fields like biology, nutrition, and health care, where they are essential to disease prevention, healing, and development.