Final answer:
Eukaryotic translation initiation factor 2 (eIF2) is inactivated by phosphorylation, which impedes the formation of the initiation complex and, consequently, the process of translation.
Step-by-step explanation:
The general translation unit that is inactivated by phosphorylation is eukaryotic translation initiation factor 2 (eIF2). Phosphorylation of eIF2 leads to a conformational change that prevents it from binding to GTP. As a result, the initiation complex cannot form properly, impeding the process of translation. This has significant implications for the regulation of protein synthesis, as it can be a control point for the translation of specific proteins or a response to cellular stress, and abnormal phosphorylation levels of eIF2 are linked to neurodegenerative diseases.