While no one wants to file for bankruptcy protections on student loans (or any other type of loan for that matter), their removal from student loans has clearly caused a systemically predatory lending system the likes of which this country has never seen, and has also enabled the intolerable tuition inflation already mentioned.
Phosphorylation is a type of cell regulation involving the attachment to, or removal of, phosphate groups from proteins, thereby switching their biological functions on or off, or making them more or less stable.