Questions: Which of the following elements is NOT correctly matched with its cellular function? nitrogen - needed for amino acid synthesis phosphorus - used for production of carbohydrates. sulfur - used for synthesis of thiamin and biotin magnesium and potassium - required as cofactors for enzymes phosphorus - incorporated into nucleic acids

The answer is the second one: phosphorus - used for production of carbohydrates.

Explanation for each option:

1. Nitrogen - needed for amino acid synthesis: This is correct. Nitrogen is a crucial element in the synthesis of amino acids, which are the building blocks of proteins.

2. Phosphorus - used for production of carbohydrates: This is incorrect. Phosphorus is not directly used for the production of carbohydrates. It is primarily involved in the formation of nucleic acids and ATP, which is essential for energy transfer in cells.

3. Sulfur - used for synthesis of thiamin and biotin: This is correct. Sulfur is an essential component in the synthesis of certain vitamins like thiamin (vitamin B1) and biotin (vitamin B7).

4. Magnesium and potassium - required as cofactors for enzymes: This is correct. Both magnesium and potassium serve as cofactors for various enzymes, playing critical roles in numerous biochemical reactions.

5. Phosphorus - incorporated into nucleic acids: This is correct. Phosphorus is a key component of nucleic acids, such as DNA and RNA, where it forms part of the backbone structure.

In summary, the incorrect match is phosphorus being used for the production of carbohydrates.