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 covalent backbone of proteins is made up of hundreds of individual bonds. If free rotation were possible around even a fraction of these bonds, proteins could assume an almost infinite number of threedimensional structures. Figure 7-1 The structure of the enzyme chymotrypsin, a globular protein.