cofactor

noun

1. 1

   A contributing factor.

2. 2

   A substance, especially a coenzyme or a metal, that must be present for an enzyme to function.

3. 3

   A molecule that binds to and regulates the activity of a protein.

4. 4

   The result of a number being divided by one of its factors.

5. 5

   (of a matrix) The signed determinant of the submatrix produced by removing the row and column containing a specified element; primarily used in the recursive definition and calculation of the determinant of a matrix.