Alright so this isn't exactly a homework question, but a strange thing I encountered in my course book :
using visible movement as the defining characteristic of life is not enough.
Movements over very small scales will be invisible to the naked eye –
movements of molecules, for example. Is this invisible molecular
movement necessary for life? If we ask this question to professional
biologists, they will say yes. In fact, viruses do not show any molecular
movement in them (until they infect some cell), and that is partly why
there is a controversy about whether they are truly alive or not.
Why are molecular movements needed for life? We have seen in earlier
classes that living organisms are well-organised structures; they can
have tissues, tissues have cells, cells have smaller components in them,
and so on. Because of the effects of the environment, this organised,
ordered nature of living structures is very likely to keep breaking down
over time. If order breaks down, the organism will no longer be alive. So
living creatures must keep repairing and maintaining their structures.
Since all these structures are made up of molecules, they must move
molecules around all the time.
What is this molecular movement all about? Indeed even the molecules inside the viruses must move by brownian motion etc. Or does it refer to movement which is not by a established force? What kind of molecular movement does it refer here which happens in virus inside the host cell but not outside?
I couldn't find anything through wiki articles...
Thanks for reading and helping.