Living Environment Regents Practice Test

What happens to the nitrogen found in our bodies' muscle and organ tissue?

1. It originates significantly from food sources

2. It is produced by body cells

3. It comes from fertilizer factories

4. It is synthesized from sunlight

The correct answer is: It comes from fertilizer factories

The nitrogen found in our bodies' muscle and organ tissue primarily originates from food sources, specifically proteins. When we consume protein, our bodies break it down into amino acids, which contain nitrogen. This nitrogen is then used to build and repair tissues, synthesize hormones, and produce various biomolecules essential for bodily functions. The option that nitrogen comes from fertilizer factories relates to agricultural practices, where nitrogen is used to enhance plant growth. While fertilizers contribute to the nitrogen content in food crops, this is not the direct source of nitrogen in human muscle and organ tissue. Instead, the nitrogen incorporated in our bodies stems from the food we consume rather than direct absorption from fertilizers or their byproducts. Understanding the correct source of nitrogen is crucial in comprehending nutrition and metabolism, especially in how dietary intake affects bodily functions.