Answer:
True
Step-by-step explanation:
When a virus infects a cell, it hijacks its machinery to replicate itself. As part of this process, the virus produces viral proteins, which can be broken down into peptide fragments by the cell's proteolytic enzymes. These peptide fragments can then be presented on the cell surface in complex with major histocompatibility complex (MHC) molecules, which can trigger an immune response to the virus. Therefore, breaking viral proteins into peptide fragments is essential in the immune response to viral infections.