[AlgebraSystem]

In a spherical protobiont with a diameter of 1.5 µm there are 3 molecules of one enzyme with a molecular weight of 250 kDa.  How high is the concentration? And how does it look in a virus (diameter 100 nm) or a 1 l water bottle?

[Babcock_Hall]

It is a forum rule that you must show your attempt before we can help you.  It would also help to establish which units of concentration one is supposed to use.  If it were up to me, I would assume molar units unless told otherwise.