What percentage of protein is nitrogen?

The correct answer is based on the relationship between protein and nitrogen content. Proteins are made up of amino acids, and each amino acid contains nitrogen. On average, the nitrogen content in protein is approximately 16%.

To convert this nitrogen content into a percentage of protein, we can use the inverse of the nitrogen to protein ratio. If nitrogen accounts for 16% of a protein's composition, then this translates to a protein having about 94% remaining that is not nitrogen. Thus, when considering protein as a whole, it can be said that roughly 16% of the weight of a protein molecule is derived from nitrogen.

This standard is widely accepted in nutritional science and forms the basis for calculations regarding protein intake and dietary needs. Therefore, the percentage of protein that is nitrogen is typically considered to be 16%.