Calcium current to amount of substance units (mol)

[gjfelix2001]

Hi there... I have a differential equation with to terms:

$$\frac{d[Ca2+]}{dt}=f\Big(\frac{3I_{Ca}}{z 4 \pi r^3 F}-k_{Ca}[Ca2+]\Big)$$


I think that the first term converts the Ca2+ (density of?) current to mol units. But, where does it comes from?

$$z$$ is the valence; in this case of the Ca2+, $$r$$ is the radius of a cell, $$F$$ is the Faraday's constant, and $$I_{Ca}$$ is a Ca2+ current, or may be density of current. $$k_{Ca}$$ is a rate with $$ms^{-1}$$ units, and $$[Ca2+]$$ is a concentration with mol units... In this case, r is the radius of a cell...

Thanks a lot...

 

[Borek]

Any context to that question? It is even hard to start thinking over some equation coming out of a blue.