Viruses fundamentally do not possess their own metabolism. Instead, they are entirely dependent on the metabolic machinery of the cells they infect.
According to scientific understanding, viruses themselves are metabolically inert and must rely on metabolic events in the cell to generate its component parts and to replicate new viral copies. This means that unlike living organisms, viruses cannot produce energy, synthesize proteins, or perform other essential metabolic processes on their own.
When a virus infects a host cell, it essentially hijacks the cell's existing metabolic pathways.
- The virus uses the host cell's resources:
- Energy (ATP): To power viral replication.
- Enzymes: To carry out biochemical reactions needed for viral production.
- Nucleotides and amino acids: The building blocks for new viral genetic material (DNA or RNA) and proteins.
Oftentimes, the cell at the time of infection is in a quiescent state, but the infection acts to change the cell's metabolic activity. Viruses actively reprogram the host cell's metabolism to favor the production of viral components and assembly of new virions. This can involve altering the cell's use of glucose, amino acids, and lipids, diverting these resources towards viral synthesis rather than normal cellular functions.
Therefore, "virus metabolism" isn't a process performed by the virus itself, but rather the redirection and utilization of the host cell's metabolic activities for viral replication.
