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.
By definition, the structure of a protein is based on the linear sequence of amino acids (primary structure) combined with how these amino acids interact with each other. These interactions occur within a single protein (secondary and tertiary structure) and between proteins (quaternary structure).