Question

Many particles, including viruses, parasites, fungi, and bacteria, do attach to cells. Following this attachment, they may reach cellular internal milieu. However not all these particles are infectious; infectious ones may be considered intracellular pathogens. In attempting to distinguish viruses from other intracellular pathogens such as leshmania, coxiella, rickettsia, Chlamydia, mycobacterium, etc… André Lwoff and colleagues set up a rather restrictive set of rules and requirements that should be followed for pathogens to enjoy being considered viruses. One of these rules is that viruses should not possess any genes that code for energy production. Why do you think this rule was included in the set of criteria that viruses should meet?

Answer 1

Viruses resemble to obligate intracellular parasites which are completely dependent on their host cell for replication. The energy generated by host cell is used by them and they exploit host's machinery to manufacture viral proteins. The vital organelles involved in protein synthesis, processing, and transport are ribosome, rough endoplasmic reticulum, and Golgi complex. These all are utilized in the manufacture of viral proteins, as well, and viruses use ATP generated by the host cell's mitochondria.