KX Modifier - SPECIFIC REQUIRED DOCUMENTATION ON FILE. KX -- SPECIFIC REQUIRED DOCUMENTATION ON FILE. (EFFECTIVE DATE 7/1/2002) This modifier may be used to indicate that specific required documentation is on file in the patient's medical record. Documentation must be submitted upon request.
Proteins are made of amino acids hooked end-to-end like beads on a necklace. To simulate. a protein, you will make a model of your protein using a long chenille stem (the fuzzy. covered wire) and colored beads.
The Rules of Protein Structure. 1  The function of a protein is determined by its shape. 2  The shape of a protein is determined by its primary structure (sequence of amino acids). 3  The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it.